Level select, all park editor objects, full stats:
Enter Up, Up, Down, Down, Left, Right, Left, Right, B, A, B, A at the "Cheats" screen.

All characters:
Enter Down, Right, Right, Down, Left, Down, Left, Down, Right, Right, Right at the "Cheats" screen.

Super Spin:
Enter Left, Left, Left, Left, Right, Right, Right, Right, Left, Right, Left, Right, Up at the "Cheats" screen.

Juice regeneration:
Enter Left, Left, Right, Right, Left, Right, Down, Up, Up, Down, A, I at the "Cheats" screen.

Low gravity wallrides:
Enter Up, Down, Up, Down, Left, Right, Left, Right, A, B, A, B, S at the "Cheats" screen.

All keys:
Enter SKELETON at the "Cheats" screen.

Full juice:
Enter BAKABAKA at the "Cheats" screen.

Never die:
Enter KHUFU at the "Cheats" screen.

Perfect manuals:
Enter QUEZDONTSLEEP at the "Cheats" screen.

Perfect handplants:
Enter JUSTINBAILEY at the "Cheats" screen.

Perfect grinds:
Enter BIGUPYASELF at the "Cheats" screen.