PokéPark Wii: Pikachu's Adventure (ポケパークWii ～ピカチュウの大冒険～ PokePāku Wii Pikachū no Daibōken) is a Pokémon spin-off video game for the Nintendo Wii.
One day, the legendary Pokémon Mew tells Pikachu that the 14 pieces of the Sky Prism have gone missing. Pikachu and friends set out on an adventure to find them in the PokéPark, which encompasses various zones such as the meadow and lava zones. Pikachu makes friends with other Pokémon and can use their abilities to clear various attractions in the PokéPark. By clearing attractions, the player will obtain pieces of the Sky Prism.
In battle, Pikachu is able to use Thunderbolt, Dash and eventually Iron Tail; these can be upgraded to become more powerful. Also, he can jump and do a flip to knock his enemy into a river, lake, etc..
Players can make friends through various mini-games as well, such as playing Chase, Hide & Seek, battling, playing Obstacle Hop, or by solving quiz questions correctly. Some of the park’s main attractions will involve Pikachu and his/her partner Pokémon racing against the clock to beat certain goals or deflecting rocks to earn points using the Wii Remote by waving it around and pushing buttons. Players also can take screenshots of the game and save them to an SD Card or the Wii Message Board
Source: Wikipedia, "PokéPark Wii: Pikachu's Adventure," available under the CC-BY-SA License.