This game is beautiful, and it was a very zen experience… most of time. Whenever I was in immediate danger my brain decided to shutdown and revert to the default control scheme on the arrow keys, leading to hilarious failures, but having the checkpoints really pushed me forward with the game.
The art really feels like a cohesive whole (squiggly animated lines particularly great), and really pulls the whole atmosphere of the game together.
I sometimes wished that the controls were a bit tighter, and a bit faster, but that might detract from the whole zen vibe you have going on.
Awesome job!