Gratuitous Shooty Game is a hobby space shooter made by the developer of Gratuitous Space Battles, reusing the art from that game :D.

This game is just a simple space shooty game where you use the left and right arrow keys to control your ship, and the spacebar to fire. Ever-more deadly waves of alien ships attack you in a suspiciously slow and predictable pattern, enabling your single spaceship to somehow overcome incredible odds and defeat all of them, given enough skill.

Watch out for bonuses that drop from alien ships, especially those cheeky ones that fly across the top of the screen.
At the end of each battle, your level score becomes a cash bonus, but you are penalized for every alien ship that flies off screen intact. Think of this as you paying reparations to the relatives of those whose houses are blown up by those pesky aliens who got away.

After each level you get to upgrade your ship using your bonus cash. Invest in better shields, better lasers, faster thrusters to move your ship, or a better rate of fire.
For budgetary reasons, your planet only has a budget for a limited number of ships, and for reasons that are unclear, only one can be launched at a time. If you run out of ships, you fail. Sadface.