U.S. drugstore Walgreens and digital agency Aisle411 have collaborated to produce a pretty compelling in-store shopping experience that makes use of Google's Project Tango.
It looks like shoppers need to create a list before visiting the store, which seems the only obvious weak point in this solution, before they're then shown a route to all the items they'd like to buy. Personalised special offers are displayed en route.
The gamification aspect looks to be limited to the shopper picking up loyalty points for following the proscribed route, but there's plenty of potential for adding further activities.
Build a set of scales into the trolley and add self scan and it strikes me there'd be no need for a physical checkout either. Here's the video.
More here en Francais, though Chrome does a reasonable job of translating the article into English.