I played this demo on a Windows 10 laptop with trackpad and keyboard.
Most satisfying level to beat: 1-4.
Level I skipped: 1-7.
Since I wasn't familiar with the mechanic, it took me a while to figure out how to open a door. I thought I was aiming close enough for the magnet to "catch" the field of the chute, or that there was some other trick like jumping or pressing an interaction button, until I realized you have to stand directly under it and throw the magnet directly up. This was tricky with my trackpad. I did not like opening doors. I also found the hub to be clunky.
The low-sensitivity mode helped with my aiming issues but did not fully alleviate them: sometimes the trackpad would completely lock up while aiming.
I thought the aim toggle might help as well, but is there something I'm missing about it or does the toggle not allow precision aiming? All the throws seem equally weak when it's on (I couldn't start a level with it because I couldn't throw the magnet into the chute) and I don't feel like I can aim correctly.
Another commenter said they wish throwing worked like Angry Birds, which I would also like, but mostly I wish I could control the entire game with keyboard alone.
I was a little disappointed to find out that throwing the magnet into the chute in normal levels does not return you to the hub.
Sometimes I'd get separated from my magnet when it locked onto something and I was trying to go with it (usually the angle doors), which was jarring.
I was confused by the keybindings not mentioning that the arrow keys are also assigned to motion, as my movement preference is arrows over WASD. Also, for reference, a common Windows accessibility setting is to make a circle around the cursor when pressing Ctrl. If pressed repeatedly, it darkens the entire screen except the cursor. This happened to me a lot trying to reset before I messed with the keybindings, as I didn't understand why pressing Ctrl once wasn't working.
For further a11y options, may I suggest a higher contrast/reduced motion mode? I honestly skipped the last level because it was dizzying to look at and I couldn't follow what was going on.