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 two images from the latest release of Proving Grounds, which has just been released on the Steam Workshop. One focusing on the map pg_dm6, a remake of an old Quake map, and a picture of the player Avatars.