This is a really mind-bending puzzle game, I like the difficulty curve a lot and you crafted some strong puzzles. My only issue is that it feels a little unnatural to reach across you keyboard to the b and r keys- the fact that it's easy to remember that b corresponds to blue and r to red is nice, but having to play minor finger gymnastics gets a little annoying. It isn't a huge deal, but maybe remapping them to something closer together or even the left/right mouse buttons would be ideal. Still though, great game, with some excellent puzzles. Nice work.