Well, I have played a fair amount of Underworld this week. Perhaps not quite four hours. It does seem like "finishing" each world takes roughly two hours, although given my recollection of the sizes of the upcoming mazes, this may not hold true!
The world I beat in this round of playing was Talorous, where some glowing blobs talked with me and assisted me in developing a plan to fight the Guardian. Well, one of them did, the future-predicting one. How did he not predict that the Guardian would ruin things? Anyway, in the process I faced a moral dilemma in having to murder the Bliy Skup Ductosnore, the guy responsible for creating new members of his species. He also has a sense of humor--he left the i on the floor after it fell off from the sign to his room. On Talorous, I made the mistake I always make--I don't realize that the picture on the wall in the lower level is actually a device I need to pick up and use elsewhere!
That quest took up a few hours. The rest of my time was spent in Killorn Keep and elsewhere, just exploring. As requested, I tried to get the serpent statue from the Goblins in the basement of the castle, but I did not succeed this time. I managed to do it the last time I played--I remember that you have to kill a whole lot of worms, then talk to the goblin leader, and then come back sometime in the future and he randomly gives you the gift. I guess no one really gets that thing simply because there's no point in going back there!
Actually, maybe there is. A reaper who has the key to the armoury is nearby, as I recall. In spite of the fact that I just hit the 11th level, I am still too weak to take him out :-(
My general thoughts on the game are quite positive. The game manages to fuse the good points of Underworld I--mainly a strong atmosphere (the ice caves seem very lonely, for example)--with the strong plot of...Well, Serpent Isle, I suppose; in that game, the plot moved forward and there are consequences to your actions. Just a few minutes ago, Dupre told me he's going to go to the ice caves and fetch water for the castle. Granted, he never actually does it, but it's conceptually neat that people are going out and doing things.
My favorite quote from the game so far is a character who found a mysterious key, and who asserts that it "looks as if it might date from the time of Minax!" If this is hyperbole, why not go all the way back to Mondain? It was only a few decades before. And if it wasn't, what dates it specifically to Minax? Does it say "DIE FOOL" on the handle? :-P
Anyway, my recollection is that it opens a door with a mean ghost and some treasure. Thus far I've acquired a magic sword, a magic vest, and some other magic thing (a shield?) but my Lore is too low to identify them. Perhaps I would be better served just raising my mana and casting to be able to cas Identify? I'll have to ponder that one.