Egg Ball No.2
From Sonic Retro
The second boss of Sonic Advance 3, Sunset Hill's boss resembles the Catcher Eggman boss in that its an enclosed arena. Eggman rolls around the arena in a giant wheel shaped machine able to stick to the walls and ceiling. While the pattern is seemingly erratic, a platform can be activated in the to allow the player to reach Eggman no matter where he is. Only Eggman's cockpit is vulnerable and Gemerl is stationed just under him.