Monster Rancher Advance is the first of the Monster Rancher games to be released on Game Boy Advance. Similar to the other Monster Rancher games, gameplay revolves around creating, raising, and fighting monsters. Due to the Game Boy Advance's limitations, players do not generate monsters by inserting disks into the console, but typing characters. Players can also create new monsters by combining 2 existing ones, just like the PlayStation versions. One of the differences between this and earlier Monster Ranchers is that Dino has been replaced with Zumms, as well as several species, such as Monols, having been omitted.
Source: Wikipedia, "Monster Rancher Advance", available under the CC-BY-SA License.