Old-skool shooter! The fools are the mathematicians. More awesome games at http://whiplash.es
It has extremely difficult controls: you move with the left and right arrow keys, you fire with the space key. Extremely extreme difficultly difficult controls I told ya.
By the glory of the power of Greyskull !! May be the power be with you !! NEVER GIVE UP !!!
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.