Having given the first game a good try, I actually found it decent enough. Flawed, but decent. The initially interesting system of combining similiar weapons quickly broke the game, though. A mid-level weapon, if common enough, could be combined into doom-bringing death machines. Add a bazillion poison gems, and dragons go down in one hit. (With an atrocious animation.)
Still, it was an ok game if one were into the genre, and slightly less buggy at launch than Gothic 3.(Which did not allow me to play for more than five minutes befor crashing. God damn you, guru.)
This would probably only enter my collection as a method of wasting time until the launch of Skyrim, though. And that post is already filled by Oblivion.
I really can't see what the problem is in losing track of the main story by method of side-quests in any game, actually. Oblivion is the best game to use for that; several hundred hours played, and I'm not even half way through the main campaign. There are so many (generic) dungeons to raid first. So many quests to take. With the level-scaling guaranteeing total freedom of exploration.
Risen was horrible in that regard. Every quest brought one closer to the end of the game. Dreadful.