The free demo is set in a Japanese zen garden which has a number of interactive elements but isn't really a game. Epic Games states:
We created Epic Zen Garden to showcase Unreal Engine 4 using Apple's new Metal API. Metal enables developers to create very detailed scenes with very low CPU overhead. Now you can easily throw thousands of individual objects into your world while maintaining high framerate. Even better, low CPU overhead means less battery usage compared to OpenGL ES. Metal also supports offline shader compiling. This means we can do a lot of shader processing on the Mac instead of having to do it every time the application starts. Add it to the high-fidelity graphical capabilities and easy-to-use toolset of Unreal Engine 4 and you have the perfect combination to create breathtaking mobile experiences.
If you have installed iOS 8, what do you think of this example of high end graphics via Unreal Engine 4 and Metal?
*Free Download now
Source: Epic Games)