Really a great game! I keep coming back for more! %100 up to lvl 27 so far, and although I'm stopping due to frustration, I'm sure I'll be dragged back.
I agree with zagreus555, excellent use of the space bar, but the puzzles weren't designed very well. There should be no guess work when solving a puzzle, but as far as I can see there were a few times when I needed to guess.