I don't get it. As a stand alone storyline it's cool, but for a sequel to halflife, it sucks. All these characters that were never in the first game are in here now. Barney, and the two sientist were not in the first game, they were the names of the models for the scientist and security gaurds. were the f*** did THREE other races come from Combine, those syth thingys (which you don't fight you see them for five seconds) and the ant lions, who just magicaly appeared out of nowhere and now roam earths beaches. chances are this was orginally planned for it's own game, they just thought that in a world of sequels, half life being a good game needed one and it would sell better. throw in couple of headcrabs, a crow bar, and some crappy references to the original and *BAM we have a game.
One more thing, tie the games together. End of HL gman put you on the train in the oblivion, and you work for him. ok, so you think, they will make a sequel that would obviously let me know what happens, or start from the ending of hl 1 No your on a train. I do recall hearing a guy saying on the train "I didn't see you get on" so asuming that means that you were transported on the train, ok but were the hell were you, that has to be about 15 years, alyx tells you that she was little, now she is around 20.
put half life 1 and half life 2 together and you have a very bad, shaky fitting storyline together.
I would be very happy if anyone could clear this up with out saying that the telportation projects caused a rift that made the combine come, that just proves my point.