Spy cam
Press [Triangle], [Square], [Circle], [Square], [Triangle], [Circle] at the title screen.

Extra trick points
Choose Grooves and press [L1] + "Up/Left" + [Circle] off a jump to get massive points.

All riders
Select "Freestyle" at the main menu. Select Sierra at the character selection screen. Select "Time Trial" at the race configuration screen. Set the number of laps to "6". Turn off all Blades, and then put Edge as Blade 2. Start the race, pause game play, then quit the race. Press [Triangle] at the race configuration screen. Press [Triangle] at the rider selection screen. Quickly press [Up], [Down], [L1], [R2], [R1], [L2], [Circle], [Select] at the title screen. A box with "All Riders Enabled" will appear near the lower right corner to confirm correct code entry.