Arcanum wasn't horribly flawed. The combat sucked and there were balance issue in the late game but the world was good.
Horrendous combat that was completely unplayable in real time and merely really bad in turn based. Generic story that had no real impact. A few good NPCs but most of them were completely forgettable. Buggy as hell with the initial release. Extremely poor character skill balance. Horrible graphics even for the time (yeah I know graphics arn't the be all end all, but don't let the game be painful to look at). I could go on but those are the major flaws that come to mind.
I really wanted to like Arcanum but it was simply a poor game. Never did finish it despite three different attempts.