Pretty small, rough project. Main areas I would try to improve:
- Character controller: it has the basic problems of a common 2D controller (if you keep pressing holding a movement input down while in mid-air against a wall it will keep you pinned).
- Feedbacks: signal to the player *everything*: enemy health, how much damage you take, how much damage you do etc.
- Onboarding: tutorials everywhere. Teach the player what the main attack does (I discovered the waves deflected the projectiles but it would be cooler if the game told you that and ideally let you try on a test enemy!)