You might've done a little sequence breaking in the wyrm ruins. You were supposed to go talk to the shade near the summoning room early on, which allows you to go through some interesting events with the magera (and gives you some sweet items if you finish the whole sequence).
The shade in the throne room never appeared.
I kept a pretty hard "we don't deal with slavers and raiders" policy throughout the game, so I guess I missed the dialogue with eithe the lizardmen or the Mageras guarding the entrance to the wyrm ruins.
Also, one of the most (if not THE most) powerful weapons in the game can be created after you kill Balkazar.
A poison weapon? Balkazar was the last thing my party did before retiring so I didn't bother.
Anyway, the game really grew on me after a slow start.
I really liked the unlinearity of the game and the multiple solutions to most problems. At the time of release it was probably the best CRPG in that regard.
All in all the game felt much closer to Ultima, Fallout and Baldur's Gate than it did to the Gold Box games. So the game was not really an evolution from the Gold Box game, with their linear, simple plots and better combat system, but rather like starting from a clean slate with very different design ideas. I guess that was partly why it failed commercially. Many of the Gold Box fans were disappointed with the combat (including me when I tried it some years after release), while those who would be a more likely target audience (if we disregard the fact that it uses AD&D rules) were Ultima fans and more "casual" gamers who didn't like the Gold Box games' focus on tactical combat and lack of NPC interaction.
I think it was a good game, but it could have been great.
The two main flaws in my opinion:
1. No fog of war. Revealing the whole area takes away the exploration aspect and the sense of danger, when you know where nearly everything is.
2. The combat. In a turn based system the player should have complete control. The lack of a grid was very annoying, especially since the game aleady uses an invisible grid for movement. I think this is a much greater "sin" than the lack of complete control in the Infinity Engine games. Since the IE games are RTwP and have simultaneous movement, a certain degree of chaos and lack of control actually feels natural.
Also, the combat in general was far too easy, which was a great shame, since the game has so many more spells than the GB games. It would have been fun if being "forced" to use your whole arsenal. As it was only the beginning, when you have but a small "arsenal" was difficult, then you rely on might and the occasional spell for most of the game, before the difficulty really turns up in the last battle without you (or me, at least) not having learnt how to use all the spells.
Minor things I didn't like:
No day and night cycle.
No need to worry about water. I would think that on the sands so hot and dry in a world called Athas getting enough water would be just as difficult as surviving the wildlife.
Things I liked in addition to the open endedness:
Getting item descriptions from that old guy in the desert.
More "grey" characters. Sure, there was a fair share of misanthropes bent on world conquest, but even they could be reasoned with. Most of the "bad guys" were merely pragmatic (too bad my party members were so insufferable righteous). It certainly was more subtle than the Gold Box games.
And the setting, of course.
This game would have been perfect for the IE engine, or a more modern isometric engine (ToEE?), I think.