You need to get to the end of the level destroying as many enemy units on your way as possible. Pick up bonuses and health packs - they are going to help you on your mission. The space commando is controlled by the arrow keys left right up and down or keys W A S & D. Use the mouse cursor to aim. Use left mouse key to fire. To choose alternative weapons (if available) use keys 1 2 3 or the mouse wheel or directly the mouse cursor.