Pokemon Gold Silver (not to be confused with Pokemon Gold and Silver the official gen 2 games) is a bootleg for the SNES.
Pokemon Gold Silver is a platformer where you can play as Waninoko (Totodile) or Chokorita (Chikorita) (though there's character select at the beginning of the game, you can switch between them any time). Chokorita can fly for a short time (despite its name it can't choke anything) while Waninoko can freeze nearby enemies for a short time. The game uses the same engine as Pocket Monster so it's similar in control and physics.
Some Pokemon act as enemies in the game including Mewtwo as the final boss though there are also some non-Pokemon creatures.