У вашего броузера проблема в совместимости с HTML5
Running the Elemental Demo from Unreal Engine 4 SDK.
R9 290X needs an upgrade, most likely going with a GTX 980 Ti from Nvidia. There is a lot of impressive content on the Unreal Engine Marketplace:
https://www.unrealengine.com/what-is-unreal-engine-4
One of the best features of Unreal Engine 4 is you can start building a first person shooter on a next-gen game engine. There's a massive community of developers already contributing their art assets such as 3d models, blueprints, textures and more.