Run. Think. Shoot. Live. Source. Black Mesa is the Half-Life 2 total conversion of the original Half-Life game. Utilizing the Source engine and its endless array of possibilities and powers, Black Mesa will throw you into the world that started the Half-Life continuum and introduced Gordon Freeman to the world as a gun-toting, bullet-dodging Ph.D. in Theoretical Physics.

u3pogee says

9/10 - Agree Disagree

+ The physics of this mod are definitely worth it! Aside from the overhaul of the textures and models, there are a ton of new elements that blend in nicely.
- The AI of the soldiers is strange, and it feels like the weapons are weakened a bit too much to make the game difficult.