Quote from kleinlukaWhat I don't quite understand is why do I have to buy a book to find out about all these things? I mean yeah, the mystery in HL2 is cool but they really should have adressed these things in the game itself. If not all, then at least some or the majority of it.
Valve has already explained quite a lot of these things, in a subtle way, ingame.
Though, they have to maintain a certain balance between story, conversations and the gameplay itself. So far they've been keeping that up quite well in my eyes. There could have been indeed, explained more through events or things you stumble upon in the game... but this might make things a bit too complicated after a while for players less immersed in the Half-Life universe.
Good point though.