While the NVIDIA Shield is far from being the device that it needs to be if it wants to capture a massive following, arguably one of the best features about the Shield is the Gamestream service that NVIDIA has been working on alongside their endeavors, which is pretty awesome. The capability allows you to stream games from you PC to the Shield, which you can play on the handheld Android console itself, or connect it to the Big Screen and play with a bluetooth controller for a more "Larger Than Life" feel. The catch to using the gamestream service currently, is that you need a few things for it to work. First, you have to own an NIVIDIA Shield, and second, you need compatible PC hardware that works with the shield and the service. Thanks to developer cgutman and his awesome little project called Limelight though, the ability to stream PC games to your Android device is now possible.
There are a few catches to using Limelight, although use of the service is not as limiting as the NVIDIA gamestream service is in its current state. You'll want to make sure you have a powerful enough Android device to support streaming games, like a 2013 Nexus 7 for example as shown by the user in the YouTube video below. You'll also want to make sure that you have a reliable WiFi connection in the house, and a good WiFi router wouldn't hurt either. Your Android device also needs to be running at least Android 4.1+. On the PC front, Limelight supports PC's that have at least an NVIDIA GTX 600 or higher GPU. It's still a tad bit limiting, but its more compatible than NVIDIA's version.
Limelight has been available for a short period of time already, but now is a better time to jump in it seems as cgutman has added in some recent performance improvements. You now have the option of choosing between two different resolutions, 720p or 1080p. You also can choose between two different frame rates, at 30 or 60fps. As the service is still in development, don't expect it to be completely flawless, not to mention that much of the quality of performance will also depend on what kind of tech you're personally using. If you wish to give Limelight a try and test out playing PC games on your tablet, you can head on over to the XDA thread for more information, and check out Limelights project page at github to get started.