Plot: Hamtaro: Rainbow Rescue is an adventure video game developed by AlphaDream for Game Boy Advance. It was released by Nintendo in Japan and PAL regions, and was set to be released in North America, but was cancelled. It is based on the Hamtaro series by Ritsuko Kawai. Wikipedia
Plot: Hamtaro: Ham-Hams Unite! is an adventure video game developed by Pax Softnica and published by Nintendo for the Game Boy Color handheld video game console. It is based on the Hamtaro anime and features much of the same characters. Wikipedia
Plot: Hamtaro: Ham-Ham Heartbreak is a video game in the Hamtaro game series for Game Boy Advance developed by Pax Softnica and published by Nintendo, as the sequel to Tottoko Hamutaro: Tomodachi Daisakusen Dechu and Hamtaro: Ham-Hams Unite!. Wikipedia