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.
A couple of strange maps that have some rather long waiting times and puzzles (with some turret sequences) it seems like a creep amusement park but abstract logic in how you progress.