Secret Mewtwo bonus stage

Complete both bonus stages in the machine that you are playing. In red field, clear the Digglett and Gengar stages. In blue field, clear Meowth and Seel stages. Then when you catch three more Pokemon or get a chance for another slot, you can reach the Secret Mewtwo bonus stage.

Once in the stage, hit Mewtwo as much as possible. If he is hit enough times, he will stop creating the balls. When this happens, you can hit him three more times to clear the stage. However, do not do this, since it will start the cycle over again. By leaving the Mewtwo stage uncleared, you may keep returning to it and get higher scores.

Evolve Pokemon in the red field

Shoot the Pokeball through the left outside loop. Each time it passes through the loop, one evolution arrow will light. When all three arrows are lit, shoot the ball into the Evolution cave. Then, choose the Pokemon to be evolved.

Evolve Pokemon in the blue field

Shoot the Pokeball through the left loop. Each time the Pokeball passes through the loop, one evolution arrow will light. When all three arrows are lit, shoot your ball into Slowpoke's mouth. Then, choose the Pokemon to be evolved.

Easier way to evolve Pokemon

After entering evolution mode, quickly hit the buttons with the flashing arrows next to them. Do not try to raise Pikachu's lightning meter. The "Ball Saver" will stay lit for awhile. During this time, after hitting a button with a flashing arrow, allow the ball to move below the flippers. After the ball is launched, if the item you are looking for is near the top, you will have a good chance of getting it. Note: If this is attempted, always make sure that the "Ball Saver" is not going to run out.

Special Evolution bonus

Enter evolution mode. Then get the menu and select a Pokemon that has a star. Go through the entire evolution process. After the Pokemon evolves, a special evolution bonus worth 10,000,000 will be awarded.

Double Cave bonus

Light up the letters C, A, V, and E to unlock the Cave bonus, but do not enter. Light up the same letters again, then enter the Cave to collect double the amount of points.

Easy 10 million point bonus

Upgrade your Pokeball all the way to a Masterball by turning on all the lights on the top half of a board. Then, try to upgrade it one more time. This is much easier than having to evolve a Pokemon with a star next to its name.

Easy Pokemon capture

Hit a Voltorb or Shellder, then hold A or B when their shadows appear.

Finding rare Pokemon

On the third ball, light up all the "GET" lights and enter the hole. This will increase the chance that rare Pokemon will appear.

Finding Pokemon
Each Pokemon has a particular location where they like to hide:
Red field
Pallet Town: Charmander, Rattata, Nidoran (M), and Poliwag
Viridan Forest: Weedle, Pidgey, and Pikachu
Pewter City: Spearow, Jigglypuff, Ekans, and Magikarp
Cerulean City: Oddish, Mankey, Jynx, and Abra
Vermilion City Seaside: Shellder, Krabby, Ekans, and Farfetch'd
Rock Mountain: Voltorbe, Diglett, and MrMime
Lavender Town: Gastly, Magnemite, Cubone, Electabuzz, and Zapdos
Cycling Road: Spearow, Doduo, Lickitung, and Snorlax
Safari Zone: Paras, Rhyhorn, and Chansey
Seafoam Islands: Horsea, Staryu, Seel, and Articuno
Cinnabar Island: Ponyta, Growlithe, Omanyte, and Kabuto
Indigo Plateau: Machop, Onix, and Ditto

Blue field
Viridan City: Squirtle, Nidoran (M), and Bulbasaur
Viridian Forest: Caterpie, Rattata, and Pikachu
Mt Moon: Zubat, Paras, and Clefairy
Cerulean City: Bellsprout, Meowth, Jynx, and Abra
Vermilion City Streets: Shellder, Krabby, Farfetch'd, and Sandshrew
Rock Mountain: Diglet, Voltorbe, and MrMime
Celadon City: Mankey, Meowth, Eevee, and Porygon
Fuchsia City: Magikarp, Goldeen, Kangashan, and Exeggcute
Safari Zone: Doduo, Nidoran (F), and Chansey
Saffron City: Ekans, Sandshrew, Hitmonchan, and Hitmonlee
Cinnabar Island: Ponyta, Koffing, Aerodactyl, and Magmar
Indingo Plateau: Geodude, Ditto, Moltres, and Mewtwo

Note: You must have a 2.1 or higher version of the Game Shark to use these codes in a Game Boy Color system.