For only knowing unity for a week this game is pretty amazing, not something I could've down when I was a beginner in unity too (I started in unity but changed pretty quickly to Godot because my computer at the time wasn't so great)
Two things you should add in my opinion:
- More feedback to hitting an enemy.
- A motive to kill enemies (I only had two instances where I needed to kill to progress)
Well, nothing more I can say given your level in unity so maybe you can rate my game too now.