Shadow Cities: Amazing and free multi-player location-based real-time strategy game. Join either the Architects or the Animators, then carry out missions warping to beacons across the globe with your iPhone/iPod/iPad during a weekly three-round battle campaign. Missions range from energy harvesting and solo entity quests to full-scale battles for territory or teamwork to control the powerful Arachne Weaver. Earn medals; advance levels; persist and discover the brilliancy of this game. And one more word: adrenaline

Check out these resources if you want to get started:
Watch the trailer
Sign up here
Read about levels
Watch out for the level 8 bug
Read this thread
"Like" my realm on Facebook to give me a vitality boost!

With determination, it is possible to achieve level 15 within two weeks.