Thanks for you feedback! I’m glad you liked my game! A health system would really improve the game but the reason I didn’t implement it is because I had the idea of killing enemies from the range of the base and then getting out of the range of the base and collect it without a weapon. Because I wanted to make getting hit a little less punishing I decided to make the player invincible, but it didn’t seem to work.
I’ll try to make a version of the game where the fuel system works as I want it to, I have some ideas to improve the enemies and the balance so the intended gameplay works, but if it doesn’t then I will consider your idea adding a healthbar and putting a win condition with the time survived.