My two decades old Pokémon game is a knockoff

I've just realised my two decades old Pokémon game (that I've never even finished) has an unusual intro/splash screen. The intro starts by displaying "Pikachu presents" and "Pokémon World", and the splash screen has "GOLD" written in a completely different font from the authentic game. Most notably, "© 2000 GAME FREAK Inc." has been replaced with "PIKACHU inc.".
I've started suspecting I've owned a knock off my whole life, which would make sense since this game is part of a "16-in-1 games" cartridge which I can't seem to find any information about whatsoever.