Gameplay
Certain minigames are needed to reach the colors, and the player must have certain Ham-Hams in their party in order to play them. For example, Sandy is needed to ride pigeons, Bijou is needed to collect falling petals, and Penelope is needed for rolling on top of cans to get across small streams.
In addition to the original Ham-Hams, the game contains some additional characters, most of which were never seen in the English anime. These include Prince Bo, who is the prince of Rainbowland (a castle that is made of clouds); Flora, or Nurse-Ham; Tux; and other various characters.
Read more about this topic: Hamtaro: Rainbow Rescue