In the Oil Ocean episode, the zone starts out with a parody of the old MGM cartoon opening titles (for a cartoon called Oil Ocean Follies). And then you see the hilarious pictures of Sonic and Tails that ensue.
The story of "Failure Cresh", a baby with a Ring monitor for a head, interrupting the gameplay.
The a capella version of the Mystic Cave Zone theme.
Game Breaker: Knuckles is broken beyond belief, able to clear entire stages by just leaping into orbit and summoning the bazooka-toting police officer from Streets of Rage to One-Hit Kill bosses. Fortunately, there's a cheat code to Nerf him and make the game more fair.