The game uses a simple preset list of passwords, each skipping ahead to a specific level. After clearing each level, the next password is displayed before moving on to the next level.
The game has a hidden more fine grained level select. Go to the options screen and, on the second controller, quickly press . If entered correctly a chime will sound. Go back to the title screen and use the while holding or to select the level.
. If entered correctly a chime will sound. Go back to the title screen and use the 
while holding