You can tell the later expansions were developed by completely different people. The original bosses are well made and animated, look cool and imposing. The new bosses. Ugh. Wooden animations, awful looking models and effects. The only bosses that look anything decent reuse models and animations from the original game (aside from Surtr, he looks pretty cool). It's a disservice to how great the original was. Looks more like a fan mod than an official release. The design of the boss encounters has also taken a dive. The original bosses had a decent moveset and most of them had at least one or two attacks you needed to learn to avoid on later difficulties, because they could one-shot you. So it was an intricate dance where you had to learn the enemy moveset and had to deal damage at the right time and dodge at the right time to win. The new bosses seem to be all about "look! we have autoattacks!" or use skills that are available to the player. I mean, compare the Hades fight to the Surtr fight. I think Surtr uses like two special moves the whole battle, rest is just autoattacks. Hell, Talos in his first few seconds uses a more varied moveset than Surter does in his whole fight.
Yes, there are serious fans. I finished Ragnarok thinking that Atlantida came later, because of the map, so I was constantly disgusted with the poverty of the "north" and in the end I left Atlantida behind, but I'm not going to give up, I uninstalled the 3 expansions and left only to "IMMORTAL THRONE". Now I would have to start all over again, but ok, I believe that what I paid for the three expansions will somehow contribute to the creation of Titan Quest 2. Such a mediocre expansions.