Rosalina's Cosmic Galaxy (name not final) is a 3D action platormer game for the Wii U. It is based on Super Mario Galaxy series and is the first 3D platformer spin-off in the Mario series.

The game retains many elements from its predecessors, as the adventure being in outer space again. However, this time Rosalina is the main character of the game. She once again appears in her Comet Observatory, and she must collect all the 135 Power Stars to save her home, her Young Master Luma and all the universe from the hands of Bowser. Rosalina can collect scattered Lumas flying around the galaxies and use them as weapons. If they die, they may reappear again in either the Comet Observatory or in any other random galaxy. She have many other power-ups, such as her Magic Wand which can levitate and pull objects. There's also some few changes, such as the color of Sling Stars are now rainbow-colored.