Untitled Magnet Game

it has been a few hours and I have managed to break the game 

but for a demo this is an amazing game controls are great puzzles are fun and accessiblity is great 

my only complaint is that it is way too easy to softlock yourself 

about the screenshot there is a bug in the game that lets you jump way higher than you are supposed to only using the magnet and please do not remove it completely it is decently hard to do and would be a neat trick in speedruns

love it, I started with the last level to challenge myself and found that some of the middle levels I struggled with a little more. definitely think the hub world that you settled on is a brilliant way of handling the approach to non-linear progression.

the puzzles definitely seem like they revolve around the magnet more than anything else with the platforming complementing it rather than overpowering it.

someone mentioned below that running into the rotating walls slowing you down being a bit of a flow-breaker. it could be cool if the magnetic ones pull you towards them and almost catapult you off. can't wait for the next update!

pros:

• puzzles are very fun
• movement and animation are very smooth
• characters have so much... well... character!
• very satisfying when I get the ah-ha! moment on a lot of the puzzles.

cons:

• the last level is too hard for me.

and that's it! this is a very fun game, and I can't wait to see what happens to it next.

I loved this demo! Here are a few things I noticed

• The game crashes when trying to rebind a controller button without a controller
• The mouse is still visible when playing with controller
• It doesn't feel great when you try to run through the rotating doors and it takes away all your speed as if you've ran into a wall

Hello fellow dev, can see the spark of something promising. Here is my feedback, hope you take it in the spirit it's intended.

Entering and Re-entering Levels:

-Currently the player gets trapped should they re-enter a level after completion. While they can use the menu to exit, something like having a 'ghost key' as the end condition should be present so players may re-attempt should they desire. Additionally, It is my belief that players should never have to touch the in-game menu for anything unless they desire, so having an in-game way to exit to the HUB would be nice - such as the door lol. Intuitively I wanted to press up at a door to enter/exit, and use the pipe to unlock the gate, but the pipe was essentially the door and the door was purely visual. 

HUB and HUB Feel:

-The game is a puzzle platformer, but the HUB is a flat hallway. All aspects of the game should provide some sort of gameplay, so the HUB is a great place for simple platforming. Players find enjoyment in just hoping around, so this would be a great place for players to cool off between puzzles with a playground of sorts. Expanding past this idea, the HUB additionally could be a puzzle itself, where players need to figure out how to unlock the gates to the levels. The pipe's could be the locks, and the player needs to figure out how to open the gates to attempt the levels in whichever order they choose.

-Level 7 is dramatically harder than the rest. If you are going to put in unrequired extra hard levels, I'd suggest marking it someway in the HUB (such as making the gate red), so players understand they are taking on a bigger challenge. Doing this helps players know that should they fail, the level was designed harder, rather than their intelligence wasn't on par.

-The finish line gate doesn't really make sense as designed. Visually, you use old timey keys in your tech facility, to open the final gate, but the individual keys are also needed to open each level? Maybe gate each level with something else (or not at all), and change the final gate to open with 'completion' powerlines streaming from the individual levels. Simply changing the key to a powered generator, and changing the Mario sewer pipes to a mail vacuum tube might help with the visual language that is trying to be communicated. Lastly on the topic of HUB art, it has parallax scrolling, so it looks like the gates are floating in place when you walk past them.

Gameplay and Gameplay Feel:

-Getting the clear condition felt abrupt in some levels, as it didn't feel like that should be just the end. I felt since it was a puzzle platformer, that I would have to get the clear condition, then platform back out of the level past the mess I made - proving I fully understood the central gimmick of the puzzle. This would allow more moments for the player to mess up in the homestretch creating those 'lmao I'm so dumb' moments that were unfortunately missing. Funny mistakes are almost required in a game that has a cute art style like this, as well as other ways to inject some levity.

-It wasn't immediately apparent that jump height differed whether or not you were holding the magnet. This made the character feel buggy until I realize it, and even still felt off knowing that detail. I can imagine some players not figuring out the variance in jump height thing, and putting the game down out of sheer bad control feel.

-One level had a metal box with a magnetism symbol on it. As most people associate metal and magnets already in their head, this redundancy actually made figuring out how the metal box worked more confusing, since it could be mistaken for a unique object to your game world with the additions.

-There were a few areas I got stuck in and couldn't platform out of, forcing me to restart the level. Restarts can feel like failures to players, so it's best your levels don't require them in instances. More testing for environment soft locks.

-Lastly, played on an Xbox controller, and the level restart was set to 'LB', but the symbol around 'LB' was round, not matching the shape of the controllers button. While obviously the most minor thing to point out, it's important to point out every minor thing, as game feel can be eroded by stacks of minor things like these that are written off as unimportant. Many AAA games leave very minor things in their games, and I believe this mentality has lead many devs to cut corners in quality in other aspects of their games. Your the teacher youtube guy, so want to help you continue to bonk out bad practices in the industry.

Overall, good work. Obviously there is still a long way to go before this is a complete game. For this to become something I'd pay money for, I'd personally want to see more personality, character, and humour baked into it. Currently, feels on the reserved end, and I'd encourage leaning into the weird once you're happy with the overall mechanics and whatever else you need to add for your videos. I never played the original, but stand alone it's got a solid framework form something good.

Tiny bit of screen jitter was the biggest outright issue I could see.

Moving while aiming makes sense but would make puzzle design potentially harder so maybe a slow down instead of a complete stop.

Something that I think would be nice would be a door entry animation, it was a bit odd watching my character run straight past the door before transitioning.

Key animation is difficult to notice, hidden by geometry/too fast a transition. Obviously an audio chime would be nice as well for some added satisfaction.

The level select has some layering errors i.e. the magnet being thrown underneath the key monitor.

I personally found the character to be a little stiff to play around with, they aren't fun in a vacuum (more of a platformer problem than a puzzler problem)

Mostly critical, but I enjoyed the demo! You're doing great and you're awesome also.

I found a bug : When you are reloading the level with ctrl. while the key is collected, but the level isnt quit yet, you can get softlocked. you spawn into the same level, just with the key missing. quitting to lobby wasnt an issue and the key was properly counted. win10 version

great place overall, enjoyed the puzzles and defiantly got the a ha moment on levels 4-6.  One thing with game being both a puzzle and platform/speed game that could lend useful in future.  For example say a levels initial impression leads you to believe it can be solved with problem/puzzle aspect when it actually requires more precision or speed.  I had a bit of this on the 4 or 5 level.  there were times the mix was confusing but if you can make it clear when what your doing isn't the correct way I'd argue it adds a lot to the game both puzzle wise and precision platform.  Sometimes great ideas will constantly be in conflict with one another, but when blended correctly mix so well it becomes the stable of the game

Couple other ideas I had for mechanics that I thought of while playing that might be helpful

- A recall option to pull the magnet in whatever direction you are, not necessarily through walls but towards you until it hits a wall.  could be something where magnet isn't in range but you can pull it/ reverse polarity a few times to get it to reach you.   this you'd pry want to make a separate power up only available on certain levels

- a lateral magnetic field type with weaker pull then when polarity is right would either speed up your move or slow you down, allowing for some interesting puzzle ideas.  You could also use this same type of field to be used to slingshot magnet

- not necessarily for these missions, but i could see if your going to speed-run/precision game  allowing user to reverse polarity much quicker so they could say bounce from one electrical field to the next and avoid death rays or something

Coming from another programmer of 4 years (not video games, but more PLC and Controls) i think your doing a great job and well on your way towards a great game.  Lots of great and helpful improvements over last iteration.

Hi Mark,

For me, the main issue is getting stuck in a level for a mistake I made and having to reset it via the reset button. Levels that are impossible to get stuck to seem more polished and taught out.

Another thing that kinda bugs me is the color of the magnets although I’m not color blind, my first thought is always to match the colors, like throw a blue magnet on blue stuff and a red magnet on the red stuff, although I know that is not how magnets work. So I thought that maybe changing the color of the magnetic field to the opposite color would be easier to catch what will interact with what.

The good stuff: I didn’t find any bugs so far Play movement feels good Magnet snapping on things feels amazing

I tested all levels and got succeeded in all but the last one, it felt much more difficult than the ones before but im also pretty dumb so that might be on me, i dont like the HUD, it takes away the flow of the game and feels like it stops you too often, maybe multiple puzzles in a row behind every door could help, the idea of throwing away the magnet for every door is interesting  but i dont think its very intuitive that throwing a magnet in a pipe would open a door, the background and design quickly gets repetetive which is only worsened by the HUD, reloading the levels feels a bit clunky and slow, maybe assign each object a default state that it returns when you hit reset and just respawn the character (if thats possible in Unity), when you aim you can trigger buttons with the magnet because of how the character moves the magnet up and down while aiming, maybe deactivate the magnets hitbox while aiming, on the last level i got the magnet stuck between the big - crate and the + magnet while it was active and then when i turned the magnet to -, it started weirdly virbrating, not a big issue right now but that could maybe lead to bugs in other puzzles

overall very positiive experience, i hope i could help

Overall, the movement and mechanics here are solid (especially with configurable controls), but I found myself noticing problems with the levels themselves. As a puzzle designer myself, I hope to be able to communicate how I think about progression in puzzle games and why something felt a bit off about the levels. 

First of all, quality of life is something that can and should be baked into the levels themselves. That means making it easy to execute not just the solution, but also any experimentation that takes place first. Most of these levels do this well, but I still feel like it's important to remember going forward. Level 3 in particular I wish was a little smaller, and had a "catch" in the ceiling so that the rising block wouldn't squish you. 

Also, being able to replay previous levels is more important for puzzle games than other genres, because you might want to process what just happened and learn from it. I would say that, in this demo, backtracking is possible but discouraged. The levels are indistinguishable from the hub, and a completed level will be missing its key entirely. These have easy fixes though, like making the (strangely hidden) level names visible from the hub, and leaving a grayed-out or dotted-line key in finished levels. 

Being able to learn brings me to my last point; while the levels have a progression of difficulty, they don't have a clean progression of knowledge. Having unique eurekas is fine, but when none of the ideas are built upon and everything is different, there is no sense of learning how to solve the game's puzzles. This leaves them feeling disconnected, and effectively, having the same difficulty for a new player, who goes in knowing none of the ideas used for solutions. Going further, when you reach a puzzle that requires you to consider the consequences of a fundamental mechanic, such as solid objects being stopped by other solid objects, the player should already be familiar with that mechanic. However, I found myself discovering and applying a mechanic in the same level, to the point where the puzzles could be considered "unfair." Don't get me wrong, figuring out new mechanics is enjoyable, but most levels turned into poking and prodding, trial and error, instead of logical thinking and planning ahead. 

On the other hand, I feel that a few of the levels just aren't good teachers. Level 2 can be solved accidentally, risking a player missing the finer points (the magnet dropping from the rotating door, and the magnet being able to fall through platforms). Level 4 is simply unclear; I found two different solutions, and I'm not sure if either of them are intended, nor did they teach me useful techniques or ways of reasoning about the game elements. "Cheese," as unintended solutions are known, are fine when they are much harder to find than the "real" solution (making for some interesting speedruns), but cheese can undermine a puzzle and its lessons when it is a lower mental hurdle than the intended solution. 

While I have pointed out a lot of design decisions that you might consider changing, there is still a lot to like, and I would encourage you to keep building on what you've learned about game design. Level 5 was probably my favorite, being a pure puzzle with a non-obvious solution, and the movement feels great, making a great environment for poking around the puzzles (although throwing the magnet might need a touch-up, I didn't realize that the mouse controlled throw direction at all). Still, I encourage you to find a way of thinking about how players approach puzzles, even if it doesn't match my own puzzle design philosophy outlined above, because player knowledge becomes more important as you add more complex levels. 

If you hold down 'F', it seems to register both down and release as valid. So the polarity changes back.

At least, it does for me.

overall great demo! it was fun, and definitely provided a few of those "aha" moments that are so necessary for a puzzle game to work. a few comments, firstly on mechanics, and secondly on the controls themselves.

let's start with a positive: the base player movement felt really nice. moving around and jumping was responsive and snappy. it wasn't hard to put the little robot where I wanted it to be.

now, a negative: the green switches. not the buttons, specifically the switches, were a little annoying. it seemed kind of weird that they would switch as soon as you were near the middle, instead of waiting for you to be on the high side. another issue I had with the switches is that after switching it, you had to go completely off the switch and back on it again to get it to switch a second time, hence the picture below.

speaking of unintuitive: magnet aiming. not being able to move while aiming was, in a word- frustrating. it felt like it added some unnecessary clunkiness to the game. if the movement is being locked specifically because of the fact that controllers are supported, I'd suggest binding jumping and holding the magnet to the triggers up top, while allowing for movement with the left joystick as regular, and allowing for aiming on the right joystick by default.

and now that we're on the topic of controllers, I tried out an Xbox 360 controller with the game and aiming was impossible. however, this seems more like a hardware issue than something that can be dealt with in the programming as far as I can tell.

every game has its bugs. the reoccurring one for me was the physics system causing the player/magnet to get stuck in weird ways, like one time I got stuck below a platform because the magnet got wedged up top while I was holding it. I got out easily by dropping the magnet, but a measure being in place to prevent that may be nice.  one time the magnet got wedged between a moving platform and a regular one after throwing it, causing the player to be stuck on one side of the moving platform.

overall, I liked it. I don't mean to come off sounding very negative as I understand that programming is difficult work, I simply wanted to point out the things that made the experience less enjoyable for me personally.  I've really been enjoying following the progress of this game on YouTube. it's given me motivation to work on some projects of my own.

to anyone who is developing a game: keep up the good work! you got this.

that's all for me! :D

Hi, I really like both the game and the devlog and would like to give feedback.

I was wondering if you could add a setting for the player to manually change the controller button promts (as in change "a" for xbox/switch to "X" for playstation) like in Outer Wilds. I have a playstation controller that acts as an xbox controller to work on pc (I read that alot of people have similar controllers) and when there's a game that automatically detects  controller type, I get xbox button promps. Not necessary, but a nice quality of life feature to add.

Other than that i really like the game and cant wait for v3.

I don't think this is how you're supposed to do it but you can throw the magnet through the little hole when the big block in the middle is up

As for feedback on the game, the general concept and feel of the game is great, the puzzles have a lot of potential and are generally executed well. 

However there are multiple levels where it is easy to get stuck, in the level above alone I've had moments where I've fallen of while the door is as you see in the picture which means a reset, I fell in the hole the box is in, a reset, I've lost my magnet next to the switch and fallen down, another reset.

A possible solution to this is making the player able to call the magnet to them, though this might not work well or require to much redesigning. 

Another solution is to simply make it harder to get to areas without the magnet if you're supposed to have it with you, though I'm not sure on how you'd implement that. 

Just loved it, II can''t believe how fluid it feels in my Macbook Pro running Windows. The great performance allows a great control using my game pad. I look forward for the harder puzzles and the music. I sense that solving puzzles has a lot of intrinsic value which is cool so no need for extrinsic rewards, wouldn't mind if there are some in the future though XD

I would love to see a bit more of variety in the future if the game gets to be very long but as a short aesthetic experience it's absolutely amazing. Can't wait for the full final version and would also love to see how you did such great optimisation and implementation.

It was fun playing this demo, but the last level i solved the whole level without even pressing the green button under the "+" cube

And There was some glitches like :

 if you hold down the restart key at the hub level, the restart arrow thing will get bigger and bigger forever.

And in the fourth level "lift up", the thing that kill the magnet, if you jumped at the very side of it while holding the throw key pointing at the left side, it won't kill the magnet and you can throw the magnet to the other side.

And the tutorial, idk if you did it on purpose but the key you take at the tutorial will stay with you the after you finish the tutorial, cuz of that key you don't have to play all level, you olny need to play 5 levels and and you will have 6 keys.

Also if you pressed the "Esc" at the tutorial level, you can skip the tutorial by pressing "return to Hub", you can also "restart" idk who would you restart the level in the tutorial

But it was a great experience, i hoped that the thing that kills the magnet was used more, and also the demo is very short i finish it in like 10-20 mins

i would like to walk while aiming 

Hi!

• The character overall feels good to control.
• The puzzles are good too, I quite like how the 90 degree doors are used with the magnet.
• Especially loved the solution in the final level. Felt quite clever when I noticed the final step of the puzzle.
• I like the art and the attractor effects

• The aiming dotted line goes behind some objects, such as the doors and the key screens in the hub area.
• When using a mouse to aim, the aiming line arch ends up feeling a bit too low when dragging the cursor farther away. Not a big deal though.
• You can re-enter the levels you've beaten, but the only way out ends up being the menu button. I suggest adding some sort of an outline/silhouette of the key when you re-enter a stage.
• In the 3rd hub level, you can crush yourself with the rightmost platform after collecting the key. It will still count as if you've beaten the level, but the death will seemingly occur after you spawn in the hub, causing it to reload.

Good work so far! The graphics are wonderful. However, on 16:10 aspect ratio, specifically 1680:1050 resolution, I can see the button prompts even when they are supposed to be offscreen and the loading swipe doesn't cover the whole screen.

If there was one change I think needs to happen it would be to allow for player movement while aiming, it made trying to line up certain throws a little more cumbersome that it needed to be

Hey Mark! If you happen to read this, it'd be quite the opportunity for me, since it seems you need some audio! My degree as a game programmer is underway, but the best way I've been able to help my teams in college has been creating music and some sound effects. I've had my hands on Ableton Live for nearly three years now. If this is a project you want to work solo, I understand, but if it interests you, please reach out to me at afoulks2002@gmail.com

Enjoyed using the new character controller, The little guy feels more fun to use. The new throwing animation also complements this new fun and faster feeling the game has. On PC,  I personally preferred changing the magnet's polarity using the RMB button as it felt weird to control both the character and the magnet using keys very close to each other. After a level is complete, you get spawned to the very beginning of the hub world. I feel that as the game gets bigger, it will be a very long distance to travel in order to get to the next level, it would be better to spawn outside the entrance of the level you just won.

When it comes to the levels, I like the newer rapid approach to solving puzzles as the 1.0 version felt quite sluggish. You would spend most of your time moving to get into position rather than testing multiple strategies. The difficulty was not easy but also not hard, it was right inbetween.

The tutorial section made me think that the level structure would  involve collecting a key and then getting your magnet buddy back to the door but in the levels you just get the key and the level ends. I almost feel like it would tie the theme together if you had to exit the level with your magnet, otherwise it feels like letting Yoshi fall in a pit while you jump to the end of the level.

This was a really good little demo! I loved playing it and was very enjoyable to mess around with for a few minutes. Of course, here's a few pieces of critique:

• The player character feels a little too sluggish for me. It feels like I should be able to traverse through .the levels and the hub a little bit faster than the set speed
• The options menu feels like it should have a back button for returning to the main menu for people who predominantly use the mouse for menus
• It feels strange to be immediately kicked out of a level as soon as you get the key. It reminds me of super mario 64 when collecting stars, but I understand the reason for the mechanic when looking at puzzle games like baba is you. Unfortunately, it feels like theres always an extra puzzle thats missing in each level in trying to get the key to an exit rather than just go to the key and you win. This feeling also links to the fact that entering a level feels like it should be an interactable option rather than get sent into the level as soon as the door opens. It's as if the game is forcing you through it rather than letting you take your time and backtrack to a different choice. It might just be me understanding the levels as "rooms" rather than areas of play.
• In level 5 and 6, it's realy easy to find yourself being stuck in an area that you (seemingly) can't leave (i.e. the block pit). I know that you are able to resart the level on a whim, but it feels like im losing progress on a silly mistake. Theres also the fact that one of the level's solutions means dropping through a gap between platforms which I wasn't clear to me due to the gap being so small that I didn't realise you were able to move through in the first place until i accidently fell through and solved the puzzle.
• The majority of puzzles were not very clear in showing how the puzzle worked, perhaps through their visibility as it's hard to see or register dark-on-dark colours.
• When throwing the magnet, it feels like it should bounce off the walls more than it does as I was trying to use angles and tragectory to throw the magnet off a wall, only to have it fall almost exactly where it landed.
• There was a small error when I first entered the hub area where I wasn't able to see the throwing tragectory. It didn't appear the rest of the times I was in the hub however.
• When I was inside of the hub, it felt weird that I wasn't able to know what was inside each of the levels or tell them apart just by being in the hub. Maybe there could be some sinage or some themes for that, mostly so that it doesn't feel like I'm choosing a level at random (even still I ended up selecting them from left to right anyway because it feels like the "right" way)

Some positives too:

• Both level 4 and 6 are really fun puzzles to solve and I thouroughly enjoyed my time problem solving with these! Level 6 especially felt hard but fair, and I felt really good when I reached that "Aha!" moment!
• The animation feels really nice, I love the little pop of the character's jump and if you can get it dangling from a magnet and move it about, it angles to the direction you would be moving and its so cute!
• I love te fact that you are always able to see the restart and changing polaroty buttons when playing as I always struggle with forgetting controls when playing a game. It's a really nice touch.

Although a lot of these are my personal preferences, I really like this game so far and I love what you have been able to create for it! Good work Mark!!

First off, fantastic game! 

• I love the creative mechanics and the way they slowly get introduced and build on one another (angled door to magnetized angled door, magnetized platforms to magnetized platforms that push buttons, etc.)
• Puzzle design was on point in that it was challenging enough to make me want to keep playing but not so challenging it was irritating to figure out the solution
• The character feels fun and flowy to control. I found myself just jumping around and seeing if I could catch the magnet mid-air. (I played with controller so my input here really only applies to that)
• The art. Oh my god the art. So pretty and consistent. Both the character and the magnet have such vibrant personalities just from their designs.

I did notice a few things, however

• Being able to move while aiming would be a nice QoL feature. There were a few times I wasn't quite lined up where I needed to be and it was a touch annoying to have to realign myself.
•  I know this is a very small sample size of levels and (based off your video, at least) it sounds like they were made in quick succession to one another but a few of them did feel very samey. I.E. use magnet to hold open door, go through door without magnet, and then change polarity to drop the magnet onto something else.

Not complaints or bugs or anything, just some stuff I personally think would be cool

• I think this set of mechanics that you currently have could really lend itself to a few levels that are a bit more fast paced and "parkour" oriented. For example: The magnet starts stuck to the ceiling, you have to change polarity, catch it mid-air, then change back, and you keep jumping from one beam to another, making sure to change polarity in between jumps. Stuff like that. Obviously that wouldn't be the whole level as this is a puzzle game but it would be a VERY fun mode of transport in between parts of the same level. This could also benefit from a sprint mode or increased player speed in general.
• I'm not sure what your plans are in regards to level variation in terms of foreground/background design but I personally would love to see these cutesy friends explore different places especially with your wonderful eye for pixel art. It would be a good opportunity to introduce zone-specific mechanics too. But, as always, more does not necessarily equal better with mechanics.

All in all, wonderful game/demo. I'm extremely excited to see where this goes and this demo placed Untitled Magnet Game IMMEDIATELY into my watchlist.

Great game feel, excited to see where this is going. A few comments:

1. The robot can't climb the switch without some runup, so if you try from right next to it, you just sputter out. Probably just a speed tuning thing

2. I don't like how the magnet can push you while you are aiming. This makes throwing the magnet while up against a wall difficult. Maybe the magnet could lose its collider while aiming?

3. I don't like having the pick up the magnet in the hub world. It doesn't really serve a purpose, and it's easy to forget, making it tedious to have to go back and get it.

4. Parallax scrolling in the hub world doesn't make sense, since it looks like an indoors space. It isn't in the final 'Thank You' room, but there is another graphical bug when moving in the right half of that room where lines appear between the tiles

5. Aiming with a mouse is fine, but I was having trouble using my built-in trackpad. It wasn't nearly as smooth

All in all though it's a pretty tight experience. Very fun to move around and interact with all the different components. Great work!

First of all thanks for the demo. As I mentioned in other comments there's still a few issues with the screen and dimensions but you're getting there.  

The puzzles had some good ideas and there is a good uses of the assets you created to weave different scenarios so far.

If I can bring some criticism, I'd say dying in the game felt unexpected. It was for the 3rd door in the hub, being suddenly crushed just felt like a cheat. I didn't expect it, and so I had no reason to try and avoid it.

It's a bit annoying by the way when you die or have to reset the whole room and having to redo steps. I know theses are short but still. Especially since some room ask you to do stuff in a very specific order so it's easy to soft be locked out of the solution with the only option to reset. I feel like it should be easier to get back on a mistake and retrace your steps.

I also feel like there's a problem with distinguishing levels. First, in the hub, if you decide to do a room later, I feel like with a more complete game it would be good to know which room is which. Otherwise you just see a bunch of doors and would nor remember which one leads to what. I think on that note the game would benefit from being more visually distinct. Having visual elements that distinguish levels, make them more themed and stuff would be good. And while I know it's just a short demo, having a basic kind of narration, you know just having an idea of who your character is, where they are, why they are collecting stuff, having like a structure with long and short term objectives would be good. Or make it part of a mystery you would solve as the game progress. It gives the player a motivation to continue and makes them want to see more, something to look forward for, create a sense of progression, etc etc. It would also probably drive you to make creative levels that can tell a bit of story while also being fun to play.

great game with interesting mechanics, really liked how the first few levels of the hub were sorta like a silent tutorial. 

the last puzzle  was a massive spike in difficulty though

two nitpicks: the level ending on picking up a key felt a bit strange -- in most other games they are used to unlock something in the current level so maybe the item that ends each room could be changed, or you need to the walk the key back to an exit door?

having to pick up the magnet at the start of each room is a little annoying, maybe spawn in holding a magnet if its a room where you want to give the player the magnet immediately?

I really liked it, the puzzles were fairly easy but the later ones definitely took some trial and error to figure out the trick. It felt really good to get a few "Aha!" moments where I suddenly noticed a detail I had previously overlooked that made the solution click into place. It was however repetitive to have to keep picking up the magnet at the start of every level and in the hub. I think if you are just going to give the magnet to the character you may as well just spawn the robot in holding it.

Feedback:
In level 2 It wasn't clear that you could drop the magnet though the one way platform onto the button
In level 7 I solved the puzzle by wedging the magnet under the large box without touching the button, if this was the intended solution the controls and physics made doing this quite fiddly requiring a number of restarts and felt like I was brute forcing the game, if this wasn't the intended solution then my bad
 

Really liked the demo! Three things stuck out for me:
1. When I switched off +/- markers in the menu, it only switched them off of the magnet and pipes; they stayed on for the magnetic fields.
2. I eventually got used to picking up the key ending the level, but it was jarring the first time for me, if only because I'm used to picking up keys partway through a level. It's not a big deal, but it was a bit jarring the first time I picked up a key and the level switch happened.
3. Like with most folks, the last level was a bit of a struggle for me. Largely because the first level involved using  a magnetic field to throw the magnet, I unsuccessfully struggled with the first two methods Erakos mentioned before finally figuring out the intended solution. I really like the final solution, but there was a period of time where I was frustrated not knowing if I had run across the intended solution or a wokaround.

Besides that, I thought it was a lot of fun! I really like that you included being able to click the left mouse to throw the magnet - it made picking up and throwing things much easier from me than aiming with the mouse and pressing a keyboard button. I had no difficulty with the mouse/keyboard setup, but I'm used to using WASD for computer games, rather than the arrow keys.

Pretty good, one minor annoyance is that the non polarized switch doors have a "cooldown" which means if I try to go through one and then immediately turn back I get stuck running against them and have to turn back and then push against them again. Noticed that immediately with the first door.

Puzzles felt honestly a bit easy and most of the time there isn't even really a way to do things that don't progress towards solving the puzzle so you could solve it accidentaly.

Last puzzle on the other hand was super frustrating. I kept messing up the throw and the timing and angle to change the polarity is relatively precise considering you have to then run quickly otherwise the block squishes you, I had the solution and kept failing for a while because I didn't succeed to apply it and that was really annoying. Another major annoyance was that the button was too far from the wall so even when the throw was successful the magnet sometimes got stuck behind the button without actually pressing it. The jump is also super tight and I had to reset multiple times because I got my magnet stuck on the other side and failed the jump. Overall a very unfun level for me and I was disappointed that it was the final level too since I expected a last more intricate level once I unlocked the final door. I get this is a demo but getting a thanks for playing when you prepare for a final challenge is a bit of a letdown especially when you come out of a very frustrating level =p