Gravity Galaxy is the tenth and penultimate world in Mini Mario & Friends: amiibo Challenge. It is unlocked by entering the amiibo Door in Level 11 as Mini Rosalina. Only Mini Rosalina can enter this world and traverse its levels.
Throughout Gravity Galaxy, the player encounters many high walls where Mini Rosalina can showcase her Lunar Launch, an ability that allows her to jump exceptionally high. Also found in large amounts are Gravity Wells, which, when tapped on, produce strong gravitational fields that attract Mini Rosalina into them. This is helpful in cases where the character has to be saved from a long fall, or where she has to pass gaps.
Gravity Galaxy is themed around Super Mario Galaxy, featuring many elements from that game: apart from Pull Stars that affect gameplay, Rosalina's Comet Observatory can be seen in the background, floating in space among other celestial bodies. The soundtrack of this world is an arrangement of the Comet Observatory theme from Super Mario Galaxy.