Proving Grounds is a TDM modification for Natural Selection 2. It focuses on First Person combat, without the RTS elements of the full game. Currently in alpha development, the mod will eventually feature multiple modes and full customisation of characters and models. This will be updated as more media becomes available.
Here are a couple of screenshots from the new map pg_lunacy by Trainee. This map has been released in v1.5a of the proving grounds mod.