This was a really cool concept and take on the jam's theme! The gameplay was a little bit confusing at first but then once I understood how the game worked then it started being more fun. The system for having upgrades was really cool as well, it adds for engagement and it was really cool to see your ship gradually get stronger and better.
The graphics are simple and I like the color scheme, but like what bymuno mentioned if you're going to use pixel graphics try to make the pixel size constant, that way the art looks cleaner and more consistent.
This was a really fun submission, I hope this one does well for the rest of the jam!