'Guinness World' was conceived by AMV BBDO, the agency behind the brand's 'Bring it to life' TV ad, and produced by digital production company Unit 9.
Users must have Google Earth, or install a plug-in. They can then begin to piece together their own planet using terrain from real-life locations such as Brazil, Nepal and Australia.
However, the experience is richer if they get their friends to participate in building their planet via Facebook Connect.
The more diverse their planet becomes, the more water droplets users discover.
When they discover the maximum 800 droplets they unlock a golden pint and become eligible to win a case of Guinness.
Paul Cornell, marketing manager at Guinness, said: "No longer can we rely on just a distinctive TV ad to generate the required level of impact, we also have to really involve and reward the consumer. The link with Google allows us to do this."
Google's applications have featured in a number of other marketing deals. Google Earth and Google Maps were used by Hasbro to create a worldwide Monopoly game in September, which initially crashed due to huge demand.