If, like me, you're coming from World of Warcraft, your initial reponses are likely to go, "wow, they make me feel important! Wow, that's a lot of major characters from movies! Wow, they let you really get into the important neat stuff quickly! Wow, this world is really, really small!" in roughly that order.
You start off on a little island in jail with Jack Sparrow. He's always in jail on this little island being bombarded with cannonfire. Every time a new player, any new player, starts. You rush out to where the same two people are always closing up their bar and getting off the island, and then run down to where captain Bo Beck turns out to have doublecrossed Jack, and gets killed by Jolly Roger. Jolly Roger is who they replaced Davy Jones with, although he's not any more copyrightable, and not really more remarkable either. And he uses undead instead of fish-people. Okay, so, undead *and* fish-people, but mostly undead.
After Jack Sparrow, you head to Port Royal (from the movies), get trained by a creepy computer rendition of Will Turner, then meet Tia Dalma (the voodoo lady from the movies) and then get papers for the Black Pearl from Elizabeth Swann. A guy gives you a ship (yes, gives, not sells) and you sail out to a little island called Devil's Anvil, and Barbossa (seeing a theme on where the characters are from?) trains you in pistols and player-versus-player combat (grab a cursed gold coin, it turns you undead, and then you can shoot at players and vice-versa), and shortly you're off to Tortuga. It looked bigger in the movies.
You meet Jack Sparrow again, then Gibbs, and then suddenly... you're not in the movies any more. You're in a MMORPG, much like World of Warcraft. Sure, you're doing things as a pirate of the Caribbean, and sure, there's still a vaguely movie-y plot involving gathering a crew for the Black Pearl, but you'll be doing it while killing off endless Navy, East India Trading Company (hereafter "EITC"), undead and generally nasty critters. Basically it becomes a pretty standard grind. That's when you realize that the four or so general flavors of enemy that you've met are about all there are in the game. Sure, Navy comes in different strengths (cadet, guard, sergeant, veteran) and EITC comes in different strengths (thug, hired gun, etc) and undead come in *many* different strengths (all of which look the same), and there are crabs *and* big venus flytrap things, but... That's basically it. Now that you've gained a few levels, it's time to grind, grind, grind. Kill eight cadets, and then ten guards, and then two sergeants, and then two veterans, and... It's, y'know, like all the other games of its kind.
And then you realize there are only a few locations. You've seen Port Royal, Tortuga, and later Cuba. And that's it for towns. The other islands are "wild" (read: tiny and covered with crabs) or hostile (read: tiny and covered with Navy or EITC and maybe a dungeony area). So instead, you'll do a bit more sailing around.
Sailing around is probably fun if you're playing as a group. It gets hard when you're a freeloader like me and can't upgrade your ship, and don't have companions to man the extra guns. The captain gets to fire the broadside cannons, but there are more cannons that you can use with more people on your ship, and I couldn't. I could do the basic grind quests (go kill me an EITC ship so you can get a copper rod off it, then a Navy ship for a single wooden board. No, really!), but I couldn't go after the big flagships and board them. Well, okay, once, but it obviously would have gotten to be too much very quickly with just me.
To add to the uniformity of the experience, there are no character classes. You're a pirate. You can use a cutlass, a pistol, and eventually (if you pay money, as I did not) voodoo, daggers and grenades. Character advancement is reasonably brisk, and the enemies aren't especially vicious or vigorous on any of the main islands, so combat is snappy, easy and fun. It is *much* less complicated than World of Warcraft, so your characters are both simpler *and* less specialized. So it's fun, it's approachable, and it has all the depth of a mud-puddle.
They've put a lot of effort into making it easy to team up, and making "kill-stealing" actually just fine since rewards are divided among all those fighting. That probably makes it a great game to play with friends, and it also seems to do fine if you have ad-hoc alliances on land or on the sea. The only winner-take-all I saw was with the big flagships, where the ship to do the most damage to them does the boarding. Still, overall it seems like team-ups were fun and simple.
My conclusions? It's a good social game, especially if you have a group of friends to play with. It's a great introduction to its genre since it makes you feel important and really uses the hooks from the movies to help you feel immersed. It has a fairly gentle transition from story to grind, so it's a good way to start hooking people who don't like such games. But it's still a MMORPG underneath, so if you don't like 'em it's just a pig in better lipstick.
Sadly, if you *do* like them, it'll just be a light snack between "real" sessions of WoW, EverQuest, et al. There may be a serious end-game, but the fact that they only have one real "story" quest and apparently it's boss-fight is currently not operating at all doesn't give me a lot of confidence. So I don't recommend playing it for the depth, the tactical balance or the endgame. But hey, you can't play WoW *all* the time, right?