This is a fun, casual game. It is not, by any means, deep, but it's still enjoyable to mess around with. You play the game as a pirate in the Caribbean pre-Johnny Depp. You can play the game during various historical settings which basically have the effect of changing how much variety there is in terms of the different national factions. The later you set the game, the more likely you'll see major French, Dutch, and English ports. By contrast, in the earlier settings, it's far more Spanish-dominated.
This can have an effect on how you play the game. With more factions, you have more ability to behave like a true pirate, sinking or taking vessels of various factions, and then doing the same to whomever they're at war with (and they're always at war with someone...). When it's just the Spanish, you have to try playing a minigame where you sneak into the Spanish port, risking imprisonment. Speaking of the minigames, they're generally good fun, if occasionally repetitive and annoying. The dancing in particular can get tedious, but at least you're usually well rewarded.
As I mentioned, the game isn't particularly deep. It's not as if you're running a wooden ship simulator. The game's graphics are dated, but acceptable. They were fortunately done in a "cartoony" style, so they age a bit better than supposedly cutting-edge visuals from the same era (2004), which now fall squarely into "uncanny valley" territory.
Anyway, it's a good game, and usually available on Steam for dirt cheap. You'll definitely get your $2-5 worth out of this title.