Hamtaro and his friends have been called to Rainbow Land to participate in an olympic event called the Ham-Ham Games. The Ham-Ham Games tournament takes place over a seven day period and consists of several different sporting events. Events include the 100m Dash, Tennis, Hammer Throw, Diving, Beach Volleyball, Hurdles, Bird-Back Riding, Pole Vault, Carrot Pull, Swimming, Archery, Sailing, Triple Jump, Synchronized Swimming, and a Marathon race. The goal is to have the team with the most gold medals by the time of the closing ceremonies. Finishing the tournament mode opens up the free play mode where the events can be played at any time.
In between events, the player is free to explore Rainbow Land where they can have chats with the other hamster denizens, search for sunflower seeds in order to buy costumes, and collect Hamigo Cards among other things.