Digimon Pocket (2000)

Digimon Pocket (called 數碼暴龍口袋版 on the title screen) is a bootleg game developed by Vast Fame for the Game Boy Color. It is about Digimon trainers who have digital monsters fighting against each other. In the game, a Digimon trainer goes across several towns in the game. A Digimon trainer has a bedroom in his house, when one day a pink aurora portal teleports him to digital monsters world.