Very enjoyable puzzle game with a steep difficulty curve in the beginning. Nice consistent art-style. The puzzles and levels were pretty well designed, too. It was enjoyable even when failing to learn why things failed.
Some of the early puzzles stumped me the hardest. I thought it got a lot easier after ~ level 5. (Spoilers) Level 12 was just the right time to add in another mechanic, for me, but maybe it could get introduced sooner.
Really good work on this!