Excellent puzzles. The trollface room puzzle was genuinely a head-scratcher for me, and I was pleasantly surprised there was MORE game after it (even if the puzzles were fairly easy from that point onwards). Puzzles were very clever, and the color-switching mechanic was well implemented.
The atmosphere's certainly there but I wish that there was more done with the story and especially the limitation. It is hard to take a game with trollface enemies seriously, and the game kind of abruptly ends.
Very good job!
Oh, before I forget, there is one small technical issue -- there's a clip bug where there's no wall on the bridge in the trollface room, letting you walk into the background (however, it's enclosed so you can't walk out of bounds).