Cool game! Fortunately I didn't encounter the bug with the mouse not working on the first level, which is nice! I do have to say though, that the second one was a bit too much trial and error, one thing you could do to change it is to make smaller grids (multiple levels) and limiting how many times the player can go through it ^^ That way it's not just a matter of trying without thinking, but an actual challenge where the player has to think to do it!
Other than that, not much to say, the art style and music were really nice ^^ Good job :D