Thanks for playing, and for enjoying! The reason I didn’t add an upgrade system is because I didn’t want to complicate the player’s controls or abilities, and keep them consistent during the course of the game. (Trying to emulate an ‘arcade’ sort of vibe)
During concepting, I was considering perhaps adding different ‘unlockable’ ships with different ways of attacking, but ended up scrapping it for time and, once again, simplicity.