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.
I have never seen a story like Half-Life. There is not nothing similar.
Its complex plot and interesting gameplay make the game perfect for those who are looking for a story beyond a shot. Also it lets you make your own opinions and theories about the universe of Half-Life, which has created the huge number of alternative adventures known as "mods".
Sorry, my english is not very good :P