In Fur Fighters, the player's job is to rescue the tiny animal babies who have been taken from their parents (in one case, it's the biggest brother) by the central villain, General Viggo. Viggo has scattered these babies all over the world, requiring the fathers (again, in one case it's the biggest brother, in another, it's the mother) to explore, confront Viggo's henchmen, and rescue all of them. The gameplay featured many unique aspects for a third-person shooter of the time it was released, most notably making each level an extremely large, expansive area that requires sometimes hours of involved exploration to locate the babies and get rid of the enemies. (Examples include a giant construction site and an entire section of a large city, complete with buildings to explore, including a complete museum of modern art.) Maneuvering through these levels often requires careful observation of the environment so as not to get lost, as well as solving puzzles to figure out where some babies might be hidden or how to gain access to more of the level. Unlike most action games of this type, Fur Fighters distinguishes itself by featuring a system where the player can, at many intervals on a level, switch between one of many animal parents. Each parent has their own advantages and disadvantages, with many having special abilities allowing them to do certain things easier. This switching-out system also makes it easier for players who are low on hit points or ammunition to switch to a more playable character.
Source: Wikipedia, "Fur Fighters", available under the CC-BY-SA License.
Additional notes: compared to the Dreamcast version, the PS2 version has new levels, cell shaded graphics, speech for the main characters, improved AI