I liked the aesthetic of the game, it is very cute. I also thought the particle effects on the attack were quite nice.
I didn't really understand the high-score chasing aspect however - it seems like your score carries over between every run?
I think if you added collisions to objects so the player has to avoid them and position around them, and made it so the game doesn't end instantly after 1 shot, there could be a fun game loop here. I didn't enjoy having to click through the main menu and intro sequence every time I wanted to play again.