Order of the vine is a T1 FM about robbing a pagan cult. The cult sits inside a mansion which can only be accessed via a long waterway, and contains a huge number of guards, and secrets.

It should be no suprise that as a T1 pagan mission, it includes quite a few soft magical elements, and a certain amount of horror. However gameplay wise, this mission is almost entirely a human mansion. The mansion is vast, with corridors that are far too wide and long by any modern design standards. The sprawling spaces actually play suprisingly well, but do look absurd in a few places.
The actual objective is a form of keyhunt, it's mostly well telegraphed, if you a find a locked door, there is often a note right next to it telling you where to go to unlock it.
That said, the objective limiting knockouts can leave some of these notes impossible to read without alerting the AI. Honestly, I would recommend just playing on hard for your first playthrough to avoid frustration.

Despite the strange proportions of the mansion, there is care and work that has been put into this missions design. A modern remake would likely squish it down, but this would almost be a shame, as it has a somewhat unique feel to it. I think this mission is very strong, especially for the time, and while it hasn't aged particularly well, it is still well made enough to be worth a look.