Super Mario and the world of Guai

Super Mario and the world of Guai is a game in the Mario series.

Plot:
Mario takes a ride into space when he crash lands on the mysterious world of Guai. He finds out that the planet is doomed to be destroyed by a dark lord, so Mario goes on a quest to stop him.

Trivia:

 * In one of the side missions, Mario can be hired to sneak into a couples house and take pictures of them for 1000 coins. This is rather creepy and disturbing for a Mario game.