Very cute game! The player character is adorable. Good music.
A couple of comments:
1. I found the use of "S" to jump a bit confusing. "W" would be more intuitive, and "E" could be used to interact.
2. I don't think there is a need for limited lives in this kind of game. The player doesn't want to re-solve puzzles already solved.
3. I would prefer slightly faster movement.