Good job!
I like the concept that you hurt yourself with the boomerangs! And great executions too!
For improvements: I think the game would benefits having more enemies, it was pretty empty (but I also a bug where I didn't had to recharge 😋)
And maybe just have the boomerang randomly go left or right? I'm not sure there is a point to have the player choose, personaly I just went close to the enemy to shot anyway ^^