"It's up to you to save the Digital World!"
Digimon World 4 is an action role-playing game which is loosely based on the movie, "Digital Monster X-Evolution" which only saw a release in Japanese.
You start as either Agumon, Veemon, DORUmon or Guilmon and can digivolve to 12 others by doing missions for the beings called "Digi-Elves" and recieving them as reward for your work for a total of 16 playable Digimon. Defeat enemies, earn bits and equip your Digimon for combat.