Super Mario Land 2: 6 Golden Coins is Mario's second adventure for Game Boy. In this game, Mario has to get his castle back from Wario by finding six golden coins that Wario scattered throughout Mario Land. This game introduces Wario.
It had visuals similar to those seen in Super Mario World and boasted many different worlds. It was graphically enhanced from the first Super Mario Land game and is generally regarded as the leading Mario title for the Game Boy.
Unlike the previous Mario title for Game Boy, the user could scroll the screen to the left, multiple powerups were available, levels were not linear (a map screen permitted players to choose levels), and the game was battery-backed.
Super Mario Land 2 was the first game to feature the Wario character. He proved to be so popular that all subsequent Game Boy "Mario" games stared Wario as the hero, prompting a spin off series.