Play as Slim Jim: at the rider selection screen in pro quest mode, press Down Down Left Right Up Up Modifier Airs.
Play as Amish Boy: complete the game with Dave Mirra, Ryan Nyquist, Joey Garcia, Troy McMurray, Mike Laird, Chad Kagy, Tim Mirra, Kenan Harkin, Shaun Butler, and Leigh Ramsdell.
All bikes: at the bike selection screen in pro quest mode, press Up Left Up Down Up Right Left Right Modifier Airs.
All styles: at the style selection screen in pro quest mode, press Left Up Right Down Left Down Right Up Left Modifier Airs.