Loving how this turned out! <3 I think that in a future update it could use an Options/Settings menu with volume sliders for sound levels and maybe adding 21:9 ultrawide support (selfish of me and unnecessary lol). Could also be helpful for Accessibility options like remapping controls!
ALSO IDEA! What if, when you have bought every upgrade in the current list, there's 1 added randomly from a range of possible "final" upgrades to buy? Like, 50000 SP or 80000 SP for "+50 Gun Damage" or "+50 Max Health" or "+50 Melee Damage" or something silly like "-1 Damage From Standing Still", but you only get 1 option per game!
Super fun game, and excellent job on completing it!