Hi, I'm new to this game. Titan Quest seems to be a much more complicated RPG than Diablo II. In the past, back when the original Titan Quest forum was still up, I only had Immortal Throne and only went through the whole game once, but I wasn't really all that good at it and had problems building my character. I did try joining the original forum but for some strange reason, I wasn't allowed to even post anything even after registering.
Now I have the full game, including Atlantis, but I have yet to play through the two new acts. I'm going to wait until I understand this game much more before I start playing again.