Adorable aesthetic, awesome premise. Things I'm hoping for if you continue developing this game:
- Jumping
- Upgrades/End-of-level scores
- Ranged attacks (for both player and enemy)
- Enemies that are larger and/or take more hits
All just suggestions, of course, but I think they'd help round out the experience a bit more. It's good so far, and it's got plenty of room to grow.