Very good game! The only problem I had is that the game really needs an "undo" button for your previous action. The controls are a bit slippery, and there was a lot of frustration with "Whoops! I accidentally pushed that block in the wrong direction," or "Oh on, I accidentally moved move square too many!" These usually resulted in having to restart a level from scratch, which was annoying on the later levels, where every little action was vital. To be able to undo your last move would be a boon. Games like this usually include such a function, as puzzle games encourage experimentation.
Otherwise, it's a great game. Great old-school graphics and sound, good challenge, and some clever ideas. Great job!