A game that has a huge loyal following but only because the game will run on old slow pc's as well as the new uber pc's.
Thats my opinion about the SP but the MP doesn't fair as well. Some of the goodpoints of the game are that it does run on slower older pc's allowing a huge fanbase of people to play, which is a good thing. But for people that are looking for a higher quality of gameplay I don't think they will find it on any of the Steam games to tell you the truth.
I really had to struggle to finish this game, it was like i was falling asleep while the unimaginative enemies tried to kill me with mundane and boring AI.
I classified HL2 as Overrated and I don't think another playthrough of the game would ever change my mind. I have never been one to fall into the hype machine for very long..although it does happen so I never say never.