Super Mario Galaxy is a 2007 platform game developed and published by Nintendo for the Wii. It is the third 3D platformer game in the Super Mario series. As Mario, the player embarks on an extraterrestrial mission to rescue Princess Peach and save the universe from his arch-nemesis Bowser, after which the player can play the game as Luigi for a more challenging experience. The levels consist of galaxies filled with minor planets, asteroids, and worlds, with different variations of gravity, the central element of gameplay. The player character is controlled using the Wii Remote and Nunchuk and completes missions, fights bosses, and reaches certain areas to collect Power Stars. Certain levels also use the motion-based Wii Remote functions.