Really nicely made game, and I had fun playing. Nice palette and the the minimalist artwork and sound effects were great. I like that you got creative in coming up with new mechanics that players probably haven't seen before and created some fun challenges from them. I had no issues getting the mechanics to work based on the in-game sign descriptions. I played this to the end twice, although I only got to 11 or 12 stars before the end sequence each time. I liked the final sequence as well.
I didn't realize at first that the checkpoints were checkpoints and avoided them due to their resemblance to spikes; as a result I thought for quite a while that the game required you to run the whole thing without dying. After figuring it out, I thought perhaps more frequent checkpoints would be nice and wouldn't detract much from the challenge.
Fun game!