I haven't finished the first episode yet but here's what I think so far. Having been irate at the lack of a PC demo I downloaded the Xbox demo, enjoyed it, then bought it on PC. I think the size clocks in at 450-500MB.
Rather than following the TV series that made the franchise uber popular, this game follows the comics, where it all began, and in doing so it has a rich comic art style to it that is actually incredibly nice to look at when playing.
The gameplay is the usual Telltale style but it has more action sequences in it due to the violent nature of the series and it is extremely gory which I quite like since they didn't hinder the spirit of the comic book with this game.
My favourite part of the game is the dialogue and story options. Many things you say to other characters is recorded for example it will say "Shawn noticed what you said" and this stays with you for the rest of the game. There are many quick decisions that have to be made, usually choosing who survives between two people, even though I hadn't interacted with these characters for long, I still felt sad when one of the characters died due to my decision to keep the other alive.
So far, I'm really enjoying this game. I hope episode 2 is just as good or even better.