All weapons Enter ICHEAT as a name. Then, press A, Right, C-Down, C-Right, C-Up, A, Left during game play. Weapons power-up Enter ICHEAT as a name. Then, press Down, Up(2), Z(2), Left, Right during game play. Surreal graphics Enter ICHEAT as a name. Then, press Down, Up, Right(3), A, Left during game play. Mutant alien Enter ICHEAT as a name. Then, press C-Down, Up, Z(2), C-Right, Right during game play. Enabling this cheat while facing a harvester will transform turn that alien into a mutant. Fat legged aliens Enter ICHEAT as a name. Then, press Left, A, Right, Down during game play. Additional difficulty levels Repeated press Left at the difficulty selection screen to access the "Very Easy" setting or repeatedly press Right to access the "Very Hard" setting.