Hidden Cities
     At  the city screen, rapidly press either Punch if you're playing
Lizzie, Kick for Ralph, or Jump for George.

City                    Hidden Stage 
Atlanta                 Suburia 
Casablanca              Palace 
Fairbanks               Underworld 
Kiev                    Exhange 
Kodiak                  Snow City 
London                  Big Ben 
Louisville              Scumlabs Bioweapons 
Moab                    Game Refuge 
Nashville               Downtown 
Phoenix                 Area 69 
Rio de Janeiro          Sunset City 
San Diego               Caleb's City 
Washington D.C.         The Capitol 

Level Select
     At  the  Character  Select screen, hold L + all 4 C buttons. Keep
holding  until  you hear a noise, then start the game. When the screen
that shows the next city appears, press Up/Down to change your country
and Left/Right to change your city.