Stargazer Colosseum is a large, domed stadium surrounded by four brightly-lit futuristic towers. Thematically set on a meteor, the stadium's battlefield and its surrounding area resemble an asteroid. The dome's inner surface is made of television sets that broadcast an image of outer space littered with numerous shooting stars.
The first round consists of rematches with all previous Colosseum Leaders. It culminates in a battle with Pokétopia Master Mysterial. Once victory is achieved, the player is granted access to the Masters Battle, a series of Trainers who all use highly advanced combinations and techniques. Once each set of Trainers is defeated, another is unlocked to challenge. The eight sets of four Trainers increase in difficulty as the series progresses. Any unlocked set may be re-challenged at any time.