Originally Posted by duga

In the first one you were a research physicist working for this company called Black Mesa. You were involved in an experiment on an alien rock brought in by the Administrator that opened a portal to Xen. In the end, you find out that the things attacking you have actually been enslaved by another race of aliens (but you don't know who). All throughout this game, this creepy guy in a suit pops up and saves you (he's the guy at the beginning of Half Life 2). In the end of the first one, he says he is impressed by you and offers you a job to work for him, the other choice is for him to kill you...so you obviously accept. He pulls you into some vortex and the game ends.

By the beginning of Half Life 2 that is seriously all you know. The genius behind the game is that it doesn't treat you like an idiot. You have to pay attention to bits of evidence that help piece the story together. There are signs, posters, and things lying around in the world that will help you put together what is actually going on. The characters in the game all assume your character knows what is going on, so no one will tell you. It's actually an incredibly intricate story.

I liked the game a lot, if you couldn't tell.