From Bulbapedia, the community-driven Pokémon encyclopedia.
Leek Game (Japanese: クキとりごっこ Leek-Stealing Game) is the name of a Pokémon-based e-Reader application. It is a minigame starring Farfetch'd. Four cards are required to play the Leek Game application: Piloswine, Farfetch'd, Nidoran♀ and Swinub.
In Leek Game, the player takes on the role of a Farfetch'd. The objective of the game is for Farfetch'd to protect its crop of leeks from other Pokémon that are trying to eat it. The game's pace speeds up as time progresses and the game is lost when the entire patch of leeks has been eaten.