This game was kinda interesting. However I just wish it could provide more diverse powerups and different enemy types and behaviour depending on the score rather than just more enemy and more damages, so we could feel the evolution of the game.
Though, while I see the use of the limitation, I don't see the theme even if this one is optionnal, it's a pity we don't have something more themed - the only connection being the enemies'projectile which looks like snowball.
But at least the game is fun to play, smooth and reminds me Undertale fights. Good work!