Monument Valley, which ustwogames just released on 3 April 2014 as an iOS app, looks almost nothing like the sandstone buttes of the southwestern United States of America. Instead, it draws its scenery from Japanese prints, minimalist 3D design, and the impossible architecture of M.C. Escher. Available for $3.99/£2.49 from the App Store on iPhone, iPad or iPod touch or at www.AppStore.com/MonumentValley (iPad 2 / iPhone 4 minimum requirement). An Android version is forthcoming.