Pretty cool, especially if you played Zork back in the day and 
remember it well, but not without problems and issues.

Cons:
Some very strange layout issues.  Yes Zork was weird, but still...
Poor construction, bad hallway joins, sloppy in many areas
Overly difficult battles with supercharged "Dedx" AI
Many frustrating and nonsensical situations
Massive key hunt (but some may like this)

Pros:
Otherworldly in an often very good way
Recreates Zork in a unique but recognizable way
Zork was nonsensical too
River and cliffs especially appealing
Nice variety of locales
Some very interesting baddies to deal with
Maze fun to get lost in

If you loved Zork as a kid, I highly recommend playing this FM.
If not, then I still recommend it but be warned that you might
not like its strong departure from more "Thiefy" fare.