Super Mario Bros. Dimensions

After the events of Super Mario Bros. 3, Bowser finds a mysterious flashing ring on the outskirts of the Mushroom Kingdom. The ring opens a gateway to an alternate dimension—underdeveloped, gloomy, and beyond Mario's reach. Bowser moves in and begins building an empire. Months pass. The mutation process he uses on his minions goes wrong: one Hyper Boo panics, escapes through the ring back into the Mushroom Kingdom, and loses its memory in the crash. Mario finds the confused green Boo and names it Polter. Polter remembers only one thing: Bowser's plan. Together they head for the alternate dimension to stop it.