HL2 is about Humor, Humor, Humor and some puzzles! And the brainwasher dude is so... brainwashing! Tonns of fun and 0 pretence. Unlike Halo 2 :)
I highly recommend this game to anyone, but buy the cheapest edition. Don't go for collector's edition. HL1 Source is a scam. Same lowrez poligons and textures, just with better physics (havok). Not enough to woo me... And both Collector's edition t-shirt and booklet suck ass. Low quality t-shirt and a promo for two large Prima books. The box itself is bleh.
But the game rocks! If you can live though awfully slow load times (this is where Halo 2 shines - fluid gameplay, not bs choppy sound, 5 minute level load times or sudden crashes).
Just tought to share the good stuff!