Levelcodes:

 Level                 Password
 ------------------------------
 Himalayas Cave        SN0W
 Himalayas Sled        SL3D
 Monsters Inc 1        M1K3
 Monsters Inc 2        P4PR
 Monsters Inc 3        M1NC
 Monstropolis Day      D4Y-
 Monstropolis Night    N1T3
 Scare Floor           BDRM
 Secret Lab 1          L4B-
 Secret Lab 2          L4BB
 Sulley's Apartment    SLLY
 The Doorvault         V4LT