Per-pet-u-al

Perpetual is an addictive retro scrolling shooter with a modern spin,there's no other shmup like it. You control an experimental rocket-jet "red X" that is attacked by perpetual waves of enemy aircraft. Try to survive and shoot as many enemy aircraft as you can in the process.

Controls

use the <left> & <right> arrow keys to control the plane
use the <down> arrow key to fire mini gun or drop a bombshell
use the <up> arrow key to boost
use <ctrl> to select weapon
lock on enemies to fire a missile
use <Esc> key to quit the game

[link]