In TakeOver, the Red Emperor, an evil dude, has hidden the story world underneath a thing called reality. You and your Facebook friends become knights and ladies, and your major quest is to rediscover the story world by doing RPG stuff like defeating the Red Emperor’s Non-Player Characters to loot treasure chests, and levelling up.
Using the Google Maps API, the entire Planet (yes, ours, the real one) is rendered as a hex grid. By moving from cell to cell, you’ll repopulate it with the story world, and take it over. But most importantly, you’ll get a talking horse with whom you’ll ride real-world territory and get into mischief. Everything revolves around riding and grinding geographical space: hex cells.
TakeOver is Free2Play, selling in-game virtual currency and awesome items for you and your horse (no ads or anything).