If you like old sailing ships, exotic locales, and underworld battles, you may just like this game.
To start, the graphics are easily good enough. They're not amazing or awe-inspiring, but they're pretty. I do find myself just examining my ship as I sail, instead of jumping straight to the action.
The gameplay is pretty good and relatively immersive. You can trade in any number of goods, from the average cheap stuff like sugar, to high-end commodities like ebony and sandalwood. Plus, there's some extent of variation in the odds and ends you can find in the street markets. If you don't want to trade, you can fight. You can ally yourself with a particular nation and do battle with that nation's enemies, you can sail the seas searching for pirates to hunt down, you can battle with the undead in the underworld, or you can become a pirate yourself and attack anything and everything you see.
Sound is pretty good, with an appropriate soundtrack and some variety of ambient sounds. You will feel like you're actually there.
The size of the islands you visit and their cities varies greatly. Cities like Redmond are giant bustling colony centers, while at the same time there are small, quaint villages like Oxbay. Unfortunately, these variations are mostly cosmetic and don't alter the gameplay significantly.
My only major complaint is the boredom factor. While there is some variation in what you can do from city to city, most of it will begin to look familiar. Each city has a store, a tavern, a dock, and a shipyard, and the services provided at these places are always the same. What I see in this game is simply a lot of unfulfilled potential. With some more attention to detail, this game could have been a truly immersive, amazing role-playing game. It just didn't happen. Regardless, I think you'll still find that this game will eat up a significant amount of your time.