OK, I'm fairly new to IF so I probably didn't get half of the references to all of the big names. Though I've since learned a fair bit about them.
The action was well paced, never let me get bored. I did get stuck for a while on a few of the puzzles (there's not that many), but given time to relax and think about them I could work them out.
The setting and story telling in it I liked, finding it easy to immerse myself into Stephen's variation on reality. (Spoiler - click to show)I liked the many references to the Illuminatus. I'll probably play it again to see if there is much variation if I do things differently.