Critical Mass is an unity 3d shooting game where enemies are coming from all sides. You are alone and you must protect yourself as long as you can. Use a machine gun and eliminate enemies as much as possible. Avoid enemy fire and survive.
To play Critical Mass, you will use W,A,S,D keys to move, left click mouse button to fire with machine gun, right click mouse button to fire with rockets, Ctrl key to aim at cursor, Shift key to run, numeric key 1 to activate the AC-130 and SPACE bar to jump.