Pretty cute and fun :)
Two things that bothered me:
- The clouds on the 2nd level were so bright and fast they distracted me a lot. I guess they could be darker and, if doing parallax, moving a bit slower than the trees closer then those clouds.
- It was a bit difficult to aim, especially into smaller enemies on level 1. I wonder if making their hitboxes (or the bullet hitbox) bigger would help with that. Or… I just have to git gud :p