Zotac has been making some pretty awesome PCs for a while now and with the latest generation of chips from Intel now in the wild, they've updated their Magnus EN970 to include an NVIDIA GeForce GTX 960 as well as a Core i5-5200U. It will also support 16GB of DDR3L, and 802.11ac networking. It's smaller than a WiiU and has enough power to play pretty much any current game on the market today.
Although this may not be the most robust unit on the market, it certainly packs quite a bit of hardware for a mini PC. While Zotac has not listed the sizing specifications for the unit, we have reached out to get proper measurements and can only assume that it is similar to its previous ZBOX units.