Barnyard is based on the animated movie of the same name. It is set on a farm where all animals can talk and walk, but only when no humans are around. The player takes the role of a new arrival, either a male or female cow, who has to finds its place inside the community.
The gameplay revolves around walking around freely in the unlocked portions of the farm, talking to other animals with exclamation points on their head and solving fetch quests for them. Some quests are mandatory to progress the plot, while others are side content that earns money to buy decorations for night festivities.
When entering more dangerous areas of the farm, there are enemies that take away life energy when touched. They can be avoided or fought by shooting milk at them. The main character has three stats that can be improved during the course of the game: life energy, milk capacity and running speed.
The game features a bicycle to help move around, and optional mini games for added challenge. Overall, Barnyard offers a unique blend of exploration, puzzle-solving and animal interactions in its Game Boy Advance format.