Developer Secrets
     From  the World Map, select a level so you are on the "Start? Yes
/ No" message. Hold L & R and input the following codes:

Cheat code:             Effect:
SLACRLOCOROCO           Open all stages
STARSLOCOROCO           Gives you 10,000 coins
ALLCOLORSLOCOROCO       Gives you all the Muimui

On Loco Editor Menu: 

SCALUDLOCOROCO          Turns on scaling.
ALLLOCOROCOS            Gives you all the parts
ATTACLOCOROCOS          Lets you use the 12 Special Loco Editor parts 
                        in Loco House (like the "toge")
LOTSOLOCOROCOS          Adds 5 locorocos of each color to your Loco House.
RADCATLOCOROCO          Adds special part editing