Gex - Enter the Gecko Game Cheats
Press [Esc] to pause the game at the central (Media Dimension) area. Then, hold H and press [Right] [Right] [Left] [Right] [Space] [Down] [Right]. Press [Esc] to resume the game, then press [F1] to display three cheat menus. Note: Cheat mode must be reactivated after completing the next level.