It's been quite a while since we saw the Elemental Tech Demo of the Unreal Engine 4, which we first saw sometime throughout 2012, but the software behind it has now finally been published on the web.
Whether the release of this was the intention of the developers is unclear, and is at best questionable, as there is not really an interface to go with the demo. You'll manually have to configure your resolution and full-screen settings through notepad, and because it comes in a portable configuration, you'll manually have to initiate the install of the VC++ 2013 runtime.
Using the tilde [ ~ ] button you can bring up the console, though many of the commands won't be all that useful. The command "Stat FPS" can be useful if you want to bring up an FPS counter though, so be sure to check that out if you're curious how well your machine is performing. To close the demo press Alt+F4, though if that doesn't work, you can always type "exit" into the console and press enter.