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.
It looks good, but I advise you to make a mod based on your maps. Downloading them separately is such an idea
Much better than the previous version but there are still some empty parts and still no reason to run around in an empty map. Like I suggested before, a bite sized mod with similar maps could work great.