One of the best games I have rated so far! Controls are easy to pick up. Ability to switch characters by pressing [space] really helps with focusing on the part of puzzle you're solving. Level designs are smart, slowly introducing new game mechanics and increasing difficulty. I seems like you really put a lot of effort to make sure that player doesn't get lost, thanks to sound and visual cues, "non-inverted" character highlight, and easy-to-read icons and tiles. Game looks incredibly good and polished. Great!