IKBase themed Single Player episode.
Key 1: Cycles between the Axe and Chainsaw
Key 2: Cycles between the Shotgun and Riot Controller
Key 3: Switches between the rapid-fire and charge modes of the Antimatter Cannon. In charge mode, hold the fire button down to wind the thing up. Release to actually shoot. WARNING: Overcharging causes the gun to explode.
Key 4: Cycles between Nailgun and Perforator
Key 5: Plasma Cannon
Key 6: Grenade Launcher
Key 7: Rocket Launcher
Key 8: Thunderbolt