In 3D Galaxy Fighters (strongly inspired by the classic Galaga series), your mission is to defend the galaxy from hordes of intergalactic invaders, which appear from the sides of the screen waves. Your ship can only withstand one hit, but you can upgrade your weapons as you destroy enemies. These upgraded weapons have their own benefits and problems, and have limited ammunition.
Enemies usually attack with small projectiles or missiles. Some of them are capable of capturing you, and there's no way of escaping from them; but if you still have a life left, you can rescue that ship and attack with two ships at a time, effectively doubling your firepower!