He must train his Digimon and battle his way through all of Digimon World until the once sparsely populated city is flourishing with different Digimon from all of Digimon World. His goal is to travel around File Island, locating all of the resident Digimon of File City who have turned feral and bring them back, raising Digimon partners in the process. Jijimon greets and asks him a few questions, the answers to which determine whether he begins with an Agumon or Gabumon. The game revolves around a young boy (the player can name the protagonist in the beginning of the game), the protagonist, who is drawn into the Digital World through his V-Pet device. Many will open shops and even sell items, some which will open playable mini-games for gaining rewards and items. More Digimon working for the city will make training and various other aspects of the game much easier. The player cannot control the actions of an unintelligent Digimon, but as it gets smarter more control over its actions is given to the player. Partner Digimon begin the game with a few basic skills, but acquire more as they progress in levels through the game. The player's partner Digimon fight the Digimon that have become aggressive due to a crisis on File Island, and some will calm down and work at the city when defeated. The other main part of gameplay is battle. Raising a Digimon well will result in the Rookie Digimon 'Digivolving' into a Champion form with better stats, while not training or raising it well will cause it to Digivolve into Numemon, a Champion Digimon with inferior stats and skills. Training is done to increase the Digimon's stats to make it stronger in battle. To raise a Digimon partner, the player must train it, feed it, let it rest, and take it to bathrooms. A Digimon partner will 'fade away' with age, and return to an egg eventually, so the player has to raise it again. The gameplay revolves around raising a single Digimon from its egg form, hatching into a Fresh, up through In-Training, Rookie, Champion, and with work, Ultimate. The player's Agumon ends a battle with an enemy Agumon.

Digimon v pet chart