This was short, but very fun. I had a blast. I think the art style was also very charming and the music got my blood pumping. The only nitpick that I have is that maybe you could've given the player character a simple running animation. (Unless the idea is that she's flying to the battle zone. If that's the case, you can disregard my my nitpick.)

I'll be honest that was a lot better than what I expected xD  Had a blast with it! Found a few glitches though... One I couldn't stop running in one direction till I died and then the red damage hue would never go away! Really good though and I loved the credits haha! 

A smooth, flowing experience.

I appreciate having zero cooldown on attacks. It was empowering.

A small nitpick on visual design, though the impact was so small it really doesn’t matter: the only times I took damage was when I misread the enemy projectile as my own attack’s splash/burst, especially the red ones.

I can’t really tell these two apart when there’s several other things happening on screen.

If either the fireworks burst effect or the enemy attack sprite could have a different color and shape (something the player can tell apart by its silhouette without looking directly at it), it would undo this. Enemy attacks could be more bolt-shaped or spikes. Or the player’s attack could burst into stars and/or stripes.

Fun little short and snappy game

The slime hitboxes on the boss felt quite egregious though; I kept getting hit by him when I thought I was under far enough and when the boss leaves the screen he can hit you to(even though it feels like he's flying up(to the sky) rather than up(to the top wall)), the rest of the game felt very easy in comparison so that was a bit odd

I'm also not quite sure why some enemies explode/dissapear when they're killed and why some stick around, I thought I was doing something wrong or if they were still alive at first before I realised they just kind of do that

I had fun