The fact that this was done in under 48 hours is nothing short of impressive, amazing work!
My game did crash when i tried to upgrade though, dunno why. 🤷♀️
Yeah this is a known bug, thanks for reporting. It happens because when you upgrade your ship and there are enemies targeting it, it technically gets deleted and a new one spawns which leaves the enemies targeting a dangling pointer that has some corrupt garbage for its value and the game crashes. Unfortunately i only found out about this after the deadline. Thanks for playing and im glad you liked it :)