Unlock the following characters by performing the corresponding tasks:
CHARACTER - HOW TO UNLOCK Amigo - Beat all missions in Story mode. Billy - Beat all missions in Story mode. Blaze - Beat the Babylon story. Cream The Rabbit - Beat the Hero story. Eggman - Beat the Babylon story. NiGHTS - Beat all missions in Story mode. Rouge The Bat - Beat the Hero story. SCR-GP - Beat the Babylon story. SCR-HD - Defeat SCR-HD in a Free Race. Shadow The Hedgehog - Beat the Hero story. Silver - Beat the Babylon story.
-To easily gain rings, select Mission 2 "Collect 'X' Rings" in Mission mode on any of the tracks. There is no limit to the amount of rings that can be collected in this mission. Continue to replay this mission until you get your desired amount of rings.
-Another way to easily earn rings is to purchase the Gambler gear at the shop and take it on a World Grand Prix; you can earn 500 rings per race. If you place 1st in the Grand Prix, you will earn 3,500 rings.
Select any character that can use a flying gear or, just use the Angel-Devil gear if available. On the second long strip that has the flying ramp, make sure you can fly by this point. Go up the ramp, fly, and hold it as long as possible. Do not fly too high or too low. This slows down the Zero Gravity trigger so when your gear hits the ground you will zoom to the Boss for a speedy hit. This is useful after several hits when the time to attack shortens.