Hey Mark! Hope you find some of this feedback helpful.
- While keys can be rebound, I recommend having right-click be set for Magnet Action. If you decide that the m+K gameplay is specifically left/right mouse to pickup/toss/swap polarization I think it will allow for quicker and easier play for folks. Having to stop movement in order to click a button to swap polarization isn't so fun.
- Movement to/from places that require the magnet is fun. Do more of that.
- For the hub world it might be fun to have each level door (or eventual subset of levels) be opened utilizing the key method that will be explored. Hub 1 can be throwing the magnet, but then eventually you need to step on a switch, get across a gap, etc etc.
- Up and Over: This is a good intro level that establishes what magnets can get through which you can't, how these switch doors work, and throwing/switching to accomplish goals. You might be able to make it less subtle that the particular asset can't be moved through in that particular direction by placing one that players need to jump over first.
- Not a Drill: This also establishes some good basics with switching the magnet to have it do multiple things away from you. I have an issue with the drill covering the shelf that the magnet can ultimately fall through. It's kind of a weird surprise vs being an established item that the magnet can go through these assets (despite what the last level accomplishes). Is there a way to create an asset that is clearly a platform/wall but has an element that indicates it's not a surface the magnet will settle on?
- Up and Away: This level might be able to help drive the above point home if the player were forced to throw the magnet from the top of the section, have it slide down and drop through the platforms and then get pulled into the switch door. It helps further emphasis that the magnet completely ignores these assets.
- Lift Up: No notes, this is a solid level for establishing the cancelling gateways.
- Weight and Pull-Me: Maybe a little too easy, but I like that it shows that there are switch gates that don't require magnets, which my brain defaulted to thinking I needed for a moment. Also it's really fun to have puzzles that require simply placing the magnet somewhere and then swapping polarization repeatedly to cause things to react as you navigate. Do more of that.
- Blocked by Block: Despite there being a quick level restart, might be nice to throw a small block in the pit next to the switch so players can jump out without needing to reset.
- Left Shift = sprint/movement boost? Yes please!
- When a Switch Pro Controller is plugged in the character jumps repeatedly and moves left. I found no way to stop this and had to just unplug and use m+k.