Very easy to pick up, was a nice challenge, awesome bullet patterns!
I really liked the polish, but i think the colors of the sprites could match a little better, you can find tons of free palettes on this site https://lospec.com/palette-list and it would greatly improve the graphics side of things if the colors were complementary in some way.
The combat was fun and balanced, the boss was cool, and the guns are all satisfying to fire!
Very solid submission, awesome job!