This is a 2.5D space shooter game (viewable in anaglyph red/cyan 3D). Shoot the incoming waves of UFOs before they get to your shuttle.
Destroy all the incoming UFOs before they reach your shuttle. Collecting power-ups may help you live a little longer...
A context menu should be shown when right-clicking or, on touch devices, long-pressing in the game. This menu especially allows to play in full screen and control the volume.