PokéPark Wii lets the player take control of a Pikachu and explore the world as a Pokémon. It all takes place in the PokéPark, a theme park run entirely by Pokémon, far from humans. The park is split into eight zones, which contain Skill Games and Attractions where Pokémon can interact and play together. Achieving a bonus score on an Attraction will earn the player a Prism Piece, which is the goal of the game.

Skill Games include Chase (capturing or tagging another Pokémon within a time limit), Battle (less like a Pokémon battle and more of a traditional boss fight), Hide-and-Seek, Quiz, and Obstacle Hop (jumping from obstacles within a time limit). Attractions are minigames that test the player's skill, but they cost Berries, which are the main currency in the PokéPark.