Barbie: Pet Rescue for Game Boy Color offers a unique storyline and mission-based gameplay similar to its computer counterpart. The story begins after a thunderstorm in Green Arbor Park, where many pets and wild animals have escaped and need rescue. Barbie takes on the role of opening her Pet Rescue Center, aiming to pick up stray animals, nurse them back to health, and return them to their owners through various mini-games.
The gameplay involves navigating Barbie through obstacle courses in a vehicle, such as a scooter, car, or boat, to reach the rescued animals. Most animals can be picked up easily, but some require completing specific mini-games, including a safari photo shoot, an ice cream craze variant of Breakout, and catching apples in a basket.
Once the animal is back at the Rescue Center, its health and happiness ratings need to be maximized. Health is treated in the check-up room with options like bandages, vitamins, food, and brushing or bathing the animal, while different animals react differently to these treatments. Happiness can be increased by playing with animals in one of three mini-games: Rascal Run-Around, Snacktime Challenge, or Critter Keep-Away.
Returning an animal to its owner involves another vehicle drive through an obstacle course, followed by a mini-game where the animal needs to be matched with its parent by reassembling a jumbled picture within a time limit. Each successfully returned animal earns Barbie a rescue certificate that can be viewed from the office. Progress in the game is saved via passwords.