This game has been on my wish list longer than any other game; I think it's been on there for years.
It comes from an interesting time in the IF community. While there are many different historical interactive fiction communities, the one I interact with the most can be traced back to IFComp, the two rec.*.if forums, and Infocom games. Between the end of Infocom and the beginning of Inform, there was a few-year 'interregnum' period with what I can only describe as pretty bad games that have not proven popular in later years.
Most of those were early TADS games (like the Unnkulia series) or AGT games (like this one). Among those are some standout gems, like Compuserve.
This game belongs firmly in the era it was published. It is an unabashed treasure hunt with a grab-bag setting and no literary aspirations. You are taking a test to get into a thieve's guild, so you wander a bunch of rooms that range from very boring (like the 'plain' room) to wacky like The Wizard of Oz, heaven and hell.
The key interesting feature is a portable hole that lets you travel through walls in every direction, making it helpful to map things out and guess where rooms might be. There are also a wide variety of strange devices.
Like most games of this era, this was designed to be tough, take a long time to replay, and require several playthroughs to time things right. I stopped and went to walkthroughs after I got stock in Oz (although later I found out I could have gotten out. But there's a plant that seems to eat you if you pass it too many times. But there's a way around that. So maybe you can beat it in one playthrough). Anyway, it's long and difficult. Club Floyd didn't finish it, and neither did one walkthrough writer.
It makes sense for its time; there were less games total, and one of this length and humor would have been difficult to find, so having something that would take forever to complete would be worthwhile. And collaborative play was more common then, with players posting hint requests on usenet. I could see this game making a great Let's Play nowawadays.
There's a lot of good in this game, so I thought of giving it a 4, but there's also a lot of silly arbitrary stuff and instant deaths, so I gave it a 3. I do think it's one of the best games in between Infocom and Inform that I personally have played.