This is one of the few anime that I've seen where the series is almost entirely dialogue driven. Despite the large swords and spears and such, you won't see them used much. Regardless, the characters are incredibly deep as the story evolves into something much deeper than you'll imagine.
This anime, taking place prior to the events in the PS2 game, is an excellent introduction to the .hack series. Don't get me wrong though, this anime is NOT just a long commercial for a video game. Standing on it's own it is one of the most powerful anime out there. Every episode is just dripping with emotion, from total despair, to total happiness.
I should also note that the music, performed wonderfully by the talented Yuki Kajiura, is simply incredible. It was the music alone that made me want to see this anime so badly.
Still, it is not for everyone. If you want hope to see all kinds of action and explosions and whatnot, look away. But if you want a mature story with depth and emotion, then this is for you.