Hamtaro: Ham-Hams Unite! 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. It launched in Japan in 2001, and later came to North America and Europe in 2002 and 2003 respectively. It was the final video game published on the Game Boy Color by Nintendo. Players control the hamster Hamtaro, who is tasked with gathering his friends and returning them to the clubhouse as well as collecting words missing from the Hamchat dictionary. The game received generally positive reception, with reviewers such as "IGN" and "Eurogamer" noting its success as both a game for children and a game that could appeal to older audiences. It was the seventh best-selling game for the Game Boy Color in Japan. It is the sequel to the 2000 Game Boy Color game "Tottoko Hamtaro: Tomodachi Daisakusen Dechu", and was followed by "" in 2003 for the Game Boy Advance which featured similar gameplay mechanics. Players control protagonist Hamtaro as they seek out the various members of his clubhouse and attempts to fill in the Hamchat dictionary. He is tasked to do this by Boss, who also teaches him basic Hamchat words. Several of the characters from the anime, such as Bijou and Oxnard, are featured in the game as characters Hamtaro must seek out. Players do this using the appropriate dialogue options to solve puzzles and appease other hamsters. Players have four Hamchat words as options by default: "Hamha" for talking, "Digdig" for digging, "Tack-Q" for tackling, and "Hif-Hif" for sniffing, all of which allow players to interact with characters and environments and may help progress the story. Hamchat words are accompanied by gestures. There are other words that players learn throughout the game that can be used in contextual situations. Characters may require words that are not yet available, indicated by question marks included in the dialogue choices, in order to fully interact with them. These words are unlocked by interacting with other characters. Sunflower seeds are a currency that can be exchanged for clothing items which Hamtaro can wear, which players can trade with each other using the Game Boy Color's infra-red port. The game features mini-games, including Ham-Jam where players can dance to the game's music using different Hamchat words, and Tack-Q Bowling.