Urban Terror: Resurgence, the revamp of the classic free FPS Urban Terror has some fresh footage of the alpha that's running on Unreal Engine.
They've confirmed it will still support Linux too, as a user asked in the comments on their YouTube video here where the developer replied with "Yup, as always!". Really nice to see them be so clear about it!
We honestly don't have enough good first-person shooters on Linux, something I've moaned and groaned about a lot.
The Alpha isn't currently public, but it looks reasonably good so hopefully it won't be too much longer until they open it up. By today's standards though, it does still look quite dated honestly. As long as the gameplay is good, that doesn't matter too much especially since it's going to remain free.
You can find more videos and screenshots in this forum post.