Haven't watched any of it so far, but the game was excellent. Looks like this is shaping up to be the best adaptation of a game yet, not that it's a very high bar to clear. It would be nice to think that the upcoming adaptations of God of War, Fallout, and Event Horizon will be quality also, but I'm not optimistic.
I believe they're doing the whole of the first game in the first series of the show. Which likely means the second series will be the entirety of the second game. That will be interesting, given fan outrage at the story of the second game. I'm not going to spoil the major story point that enraged the fanboys (and would advise you to not look it up if you're enjoying the show), but the story prominently featuring a trans character unsurprisingly didn't go down well with the more reactionary element of gaming fans.