The last time we mentioned Master Spy was about a year ago when the game was still gestating on Steam Greenlight. It's the story of sneaking past guards and cameras and dogs, using an invisibility cloak for Max Evasion Power, all to a soundtrack of ’80s synth. Our Graham has compared it to Gunpoint and Snatcher, which I think gives you as good an idea of what to expect as you're gonna get.
This is the work of Kris Truitt and John Coxworth, an indie duo who worked together previously on a Logan's Run-like browser game called The Carousel. It's wonderful - check it out here. You can also have a mess around with an early prototype for Master Spy in web browser form right here.