Here's my feedback:
- it would be nice if when you finish a level and return to the hub, you spawn in front of the door for the level you were just in, so you don't have to walk all the way back over from the left each time.
- it's possible to make the level unbeatable, e.g. as soon as you get the magnet by throwing it to the left through the door. Maybe have a prompt pup up on the screen telling you to restart when the game detects a situation in which the level has become unsolvable.
- it seems like the +/- symbols on the beams are always on regardless of the setting for them. the magnet's symbol turns on and off fine.
- I love the feel of controlling the character, and was surprised by the difficulty & satisfaction of solving the puzzles; very clever stuff! love the graphics too and can't wait til it has sound effects :D