Cool game! I love the music and the visuals. The shader needs some polish as lighting is a bit inconsistent.
I found a few bugs, and kinda cheesed the game by upgrading speed first. A nice drawback mecanic would be nice! Like, maybe upgrading speed also makes enemies surround the player, or projectiles bigger and longer range!
Really enjoyable base game vibe though so I'm glad you shared this :)
Sorry for not commenting before I was really not finding the time to review :')