Pac-in-Time (Game Boy)
Pac-Man's hallucination after eating some bad power pellets.
Enter LVSPM as a password. It will register as invalid. Now enter any valid password. Once in a level, pause, highlight any item in Pac-Man's inventory, then hold A and press Up to increase the level number at the top, or press Down to decrease it. Unpause to go to the selected level.
Disabled Super Game Boy Command
Super Game Boy command 71 ICON_EN with bit setting 01 will disable the player's ability to change palette settings. Game Boy Game Genie codes FE4-D4B-80A + 424-D5B-F7F will replace ATR_BLK, which will re-enable this function. The command is called though it never reads from the joypad registers.