Named Game of the Year by over 50 publications, Valve's début title blends action and adventure with award-winning technology to create a frighteningly realistic world where players must think to survive. Also includes an exciting multiplayer mode that allows you to play against friends and enemies around the world.
Mod Percentage: History: 35% Mod: 15% Maps: 5% Sound: 0% Textures: 0% Models: 0% Effects: 0%
Little notice about game engine change from HL1 to HL2.