I finally finished last night.
I really enjoyed the game, and look forward to Book II. You guys really nailed what you were shooting for, as I think you've perfectly captured the "old school" RPG feel that you were going for.
I spent some time thinking about what I might add to a "constructive criticism" post, and didn't come up with much. If there was one thing I would change, it would be the walking speed of the character. I note this not because I found it particularly bothersome when I played through -- I explored the world exhaustively and happily did ever quest, fully mapping each quadrant. I think it was only around the time I got the 4th key that I said "bag it" and just went straight to the citadel.
I think though that the walking speed really limits the replayability for me. I enjoyed it, and would enjoy playing through a few more times with different character types (and might still do so), but I can't see myself chugging through all of the side-quests a second time, just because of the distances involved.
Kudos to you. Can't wait to see what you do for an encore.