The plasma gun can be used to climb along walls (a technique called plasma-climbing). The vertical climb is the most basic variant. The successive recoil of the gun's rapid fire then lifts the player up the wall. By various combinations of direction-keys and mouselook horizontal and diagonal paths are possible as well. Expert performers can change the directions of travel en route, climb down and up again, climb along curved walls, and hit high walls from mid-air to plasma-climb in any direction.