This Gamasutra article written by a team from Intel entitled "Mars Sucks - Can Games Fly on Google Earth? " explores whether Google* Earth could be used as the foundation of a video game (and beyond current applications such as “Find Skull Island” and "EarthContest"). Their prototype is simple:

Martian robotic spacecraft are invading Earth and sucking up humans for experiments! We were able to capture one Martian spacecraft, which we need you to pilot in an attempt to blast other Martians out of our atmosphere. The Martians are being sent messages that direct them to their next target. Your mission is to decipher the messages, and blast these Martians before they can suck people off the planet. Stay tuned for intercepted Martian messages! (...) We decided to overlay an image of a Martian craft cockpit over the Google Earth window and let the standard Google Earth controls handle moving around the globe. In the cockpit, players see a sequence of clues about the location of each Martian invader.

The article describes more technically the architecture of such project. What is interesting is their conclusions:

We learned that very simple games and casual games are possible now on Google Earth. We also learned that Google Earth is not yet ready to be the foundation of a serious action game. (...) As we write this, rumors are that Google is planning to release an application programming interface (API) for Google Earth, and we hope that will indeed happen soon. That step would really unleash the potential for building games and other applications over Google Earth. With the API release, we are hoping to find it’s much easier to display text on the screen and handle mouse events.

Why do I blog this? what find important here is the flexibility that can hopefully exist with such platforms that could be tinkered, modified and eventually that would the creation of innovative mash-ups.