- every power-up from Super Mario Galaxy will return
- Cloud Mario: Summon 3 clouds by shaking the Wiimote
- to get more clouds, you must pick up another cloud power-up
- Fluffy Bluff and Cloudy Court Galaxies feature the cloud suit
- levels feature blowing wind that will move your clouds
- clouds disappear after several seconds
- ground pound through clouds
- lose cloud suit if you touch water
- co-op called Co-Star mode
- player 2 uses Wiimote to shoot star bits, collect objects, help Mario jump higher, and hold enemies in place, kill/stun enemies by shaking Wiimote as you hold onto them, tickle NPCs
- Player 2 can use d-pad to send cheers and other messages through player 1's Wiimote speaker
- Hint TV: a quick video plays on TV screens in the game to show you how to complete an area
- Cosmic Guide: The Cosmic Witch (which resembles Rosalina in the trailer) takes over controls to play the game for you
- Cosmic Guide appears if you die a certain amount, or if you are stuck in a particular section for a long time
- if you use the Cosmic Guide, you'll get a bronze star at the end of the level, instead of the gold
- press the plus button to end Cosmic Guide control
- drums added to the music when you ride Yoshi
- uses the same graphical engine as Galaxy