Unique idea! I really love the use of the scrolling wheel, as it's usually ignored in many games. I do have some problem though: sometimes my magnet would stuck inside the wall, and is it just me or is the screen size of the game is quite wrong? I also have some small suggestions: maybe let the player lock the magnet by clicking it, as I had some trouble distinguishing which magnet is which , and what do you think about adding even more magnets? The rest of the game is awesome, I love it!