The idea is interesting... but the execution lacks gamefeel and a goal.
I get that the objective of the game is "screw attack" as much enemies as possible, but the only fail state is letting them hit you which you can avoid entirely because the screw attack has barely any cooldown so you can spam it indefinitely, there's not much challange.
The game could be way more fun if you added said cooldown (maybe after the player hits the ground they'll need to wait half a second before making another jump), make the player loose if an enemy reaches the bottom of the screen (plus them hitting you while you're not screw-attacking) and add a score or time limit.