Title: Warning Forever
Warning Forever is another game I consider a freeware classic. Along with Facade and Nitronic Rush, it was one of the games that introduced me to indies. Warning Forever is a bullet hell SHMUP with a cool vector graphics style. But it's not like any other SHUMP you've played. This is the David and Goliath version: just your tiny ship against one boss.
Infinity Danger), I prefer the vector style of the original. You can download Warning Forever here.
*The controls are a bit weird. Z is to fire (and select menu options), X is for slow more precise movement, D activates an aiming mode that allows you to aim at the boss as you move and alters the spread of your fire. F pauses. Arrow keys move.