The Shield console runs on the Android TV operating system, allowing users to access the Google Play store of apps and games. The streaming TV box comes with a controller and around 50 optimised games will be available at launch.
Nvidia claims its Shield console is 35 times more powerful than the Apple TV, thanks to its Tegra X1 processor, and compares favourably with consoles such as the PS4 and Xbox One.
But while the Shield claims to be able to comfortably handle games such as Crysis 3 in 1080p, it can also be used as a 4K video streamer. It's capable of 4K playback at 60fps, and promises to work with all current codecs: Google's VP9, H.264 and H.265.
Nvidia has also said that Netflix and Google Play Movies will be available on the console in the future, the former at least giving access to some 4K content.
What's more, the Shield console can support high-resolution audio up to 24-bit/192kHz over HDMI and USB, and will also upsample audio to 24-bit/192kHz via USB.
MORE: How to watch 4K content: on TV and online
Other specs include 16GB of onboard storage, plus a microSD card slot that can accept cards up to 128GB, Bluetooth 4.1, two USB 3.0 ports, microUSB, Ethernet and an HDMI out port for connecting to your TV.
The Nvidia Shield games console will be available from May in the US for $199.
No UK pricing or availability has been announced, although our sister title Stuff has been told Europe can expect to see it shortly after the US.
See all our games consoles reviews