Nice game! I liked that there were upgrades and the enemy movements (particularly the red enemies and boss) were especially nice. Music was good and the boss battle was great! I really appreciated that the player's hitbox was pretty small so you could dodge a lot better (especially for the boss).
Like others mentioned, the text was broken for some reason. Maybe you didn't package the font with the game?
Also, it doesn't seem like I could take damage. My shields would go away if I got hit but, even without them, I never died.
Other than that though, great jam submission!