The Egg-Go-Round (エッグゴーランド Eggu Gō Rando) is the sixth boss of Sonic Advance 2, greeting you at the end of Techno Base. Four platforms, two grey and two orange, circle around the Eggmobile, and each have a blue light on them. The lights on these platforms will turn red, causing something to happen to the platforms: the orange ones show spikes momentarily; the grey ones spin around. Eggman will also shoot bullets at you to make things more difficult.
Your job is to avoid all these traps to hit the Eggmobile the usual 8 times (6 on Easy), but the only way to reach him is to jump on one of the platforms while its light is blue and then jump on the cockpit to do damage; hitting anywhere else on the Eggmobile won't do any damage. After the first four hits, the platforms become more erratic. It's harder than it looks.