I think you've got something mixed up. The Avernum series was a set of RPGs, but they were a remake of the creator's earlier Exile series, not a Flash game. (Exile I: Escape from the Pit was released in 1996, long before Flash was viable for this sort of game.) They weren't procedural at all, either; the content was all handmade.
Exile was my jam. I could never quite get used to Avernum, much as I liked being able to see many more tiles on one screen.
Part of it was the controls: I preferred a proper top-down view over isometric, but the main reason was probably the fact that parties were smaller. In Exile, a party could be 7 characters (I think), and it made the combat feel much more tactical.
Still, both the Avernum and Exile series are amazing, and I can highly recommend them. If you're starting fresh, Avernum 3 is probably a good one to start (it's also the on iPad and decently playable).
