Pokemon Stadium (North America)

Successfully complete Gym Leader Castle and Stadium modes. Pikachu, Blastoise, Charizard, Venusaur and Mewtwo will now appear on the title screen.

Get all 151 Pokemon in the hall of fame.

Immediately after you choose a move and you want to go first instead of the CPU, hold L and press A. This works about 50% of the time, mostly in the Pika Cup.

If you use an attack that you know you will kill the opposing Pokemon but will hit you with the recoil, make sure that your Pokemon has at least 20 HP left. Use the attack and you will not suffer the recoil damage.

Successfully complete R-1 mode, defeat Mewtwo, and complete R-2 Mode, and defeat Mewtwo again. Enter the gallery screen, then hold L + R and highlight the "Print" option. Keep holding the buttons until "Print" changes to "Bonus" to access sixteen more stickers.