Military Conflict: Vietnam, Fan made trailer.

Military Conflict: Vietnam, a Source game. Made by Dust Fade. Those who have played Counter-Strike: Global Offensive ( Currently Counter-Strike 2 ) might see a similarity with it. As it runs on the same engine as CS:GO.
The game is meant to be played online. A PVP, but you can also play against bots. With a huge variety of guns and beautiful maps to choose from.
The game is currently a work in progress. So a lot of stuff will be changed in time. I personally hope for Single-Player missions.
Recently, they added zombie game mode, where the mission is to survive waves, and waves of hordes!
Grab the game from Steam, and try it out for yourself! And no, this is not a paid promotion. I just personally enjoy the game a lot!