Wario Land II Game Boy Color

The game features the return of Wario's nemesis, Captain Syrup. Early one morning, she and a few of her soldiers, the Pirate Gooms (Spearmen, which are holdovers from Wario Land; several different levels deal with defeating a giant Spearman), sneak into Wario's Castle and cause havoc. They steal his precious treasure, set off his giant alarm clock, and leave the tap running, flooding much of his castle. After Wario wakes up and figures out what's going on, he gives chase across the surrounding lands.

The game is noteworthy for several unique features. Unlike in most video games of the time, Wario is fully invincible throughout the course of the game, and will not lose lives. The game's challenge comes mostly through impeding player progress by implementing physical obstacles, puzzle-solving, paths blocked by coin or treasure locks, or forcing Wario back to previously-visited areas. By finding hidden exits in some stages, the player can change the direction of the game's plot (loose as it is) and uncover different endings, as well as find more treasure. In addition to the Really Final Chapter, five other endings can be unlocked by collecting all the treasures. An enemy-themed Simon Says minigame based on the Game & Watch game Flagman can be unlocked by collecting all the picture tiles.

Source: Wikipedia