The 1 Player Mode is a simple VS mode throughout the game. There are five different levels of difficulty, with each difficulty adding more characters as you go through. Playing through the story mode, you play as Ash Ketchum on his Pokémon journey with his 3 Pokémon, battling through Panel de Pon and trying to defeat your opponents. In total there are 16 stages, each of which increasing in difficulty and the Pokémon they change vary in with the difficulty

The first stage has you pitted against Gary Oak. This is your simple basic stage so it should be easy

Next you're pitted against the gyms and as such, your first gym match is against Brock, the Rock Gym Leader

Continuing the gym matches, you go against Misty, the Water Gym Leader

Continuing the gym matches, you go against Lt. Surge, the Electric Gym Leader

Continuing the gym matches, you go against Erika, the Grass Gym Leader

Continuing the gym matches, you go against Koga, the Poison Gym Leader

Continuing the gym matches, you go against Sabrina, the Psychic Gym Leader

Continuing the gym matches, you go against Blaine, the Fire Gym Leader

Pausing in the Gym Matches, you end up going against Tracey, the Pokémon Watcher from the Orange Islands

Again pausing in the Gym Matches, you end up going against Jessie & James as in the animé

Completing the gym matches, you go against Giovanni, the Ground Gym Leader

After the Gym matches you end up against Ritchie, the rival similar to Ash

Going into the match against the Elite Trainers, you go against Lorelei, the Ice Elite Trainer

Ending the matches against the Elite Trainers, you go against Bruno, the Fighting Elite Trainer

Finishing the matches full circle, you go against Gary but with evolved Pokémon

The Final Match is against the Ultimate Pokémon