All Levels:
Enter "XXX RATED CHEAT" at the cheat menu.

State Select:
Enter "MASS HYSTERIA" at the cheat menu.

All bikes:
Enter "65 SWEET RIDES " at the cheat menu.

Unlock New Characters:
Once again, enter these into the cheat menu.

AmishBoys Bikes- AmishBoy1699
HellKitty's Bikes- HellKitty487
Itchi's Bikes- Itchi594
JoyRides Bikes- Joyride18
Karma's Bikes- Karma311
La'tey's Bikes- Latey411
Manuel's Bikes- Manuel415
Mika's Bikes- Mika362436
Nutter's Bikes- Nutter290
Rave's Bikes- Rave10
Skeeter's Bikes- Skeeter666
TripleDub's Bikes- TripleDub922
Twan's Bikes- Twan18