Before I begin...
I have played PP for a year or so now, but not more then a few months at a time. I recently returned to Hunter, but things seem to have changed. Anyway, I'll just cover basics and I won't get into detail about the actual puzzles:
Many people are who haven't tried this game usually have one of two reasons: They either dislike the graphics or dislike the puzzles.
Now, not liking puzzles is understandable, but not trying a game because of graphics has always been stupid in my book....however, to each his own and I won't say anyone is wrong for their reasons. If you do like puzzles, however, you might want to check this game out at least.
Everything in this game is pretty much a puzzle, minus some of the parlor games, and each puzzle is completely different then the others.
On a ship, teamwork is the key to winning battles to recieve booty and you must complete duty puzzles to contribute to the ship. The better you do, the more you help out. There are a total of five puzzles on the ship: Bilging, Sailing, Carpentry, Gunning and Navigating. The first three you'll have access to are the first three mentioned and as you practice the others with the Navy, ships where you can practice your skills without worrying about hindering others since it does not attack, you will eventually be allowed (as long as you are good) to do them on actual player ships.
Once you grapple, you'll then have to do another puzzle out of two (Swordfighting or Rumble, depends on the enemy ship) where you can team up and attack others just as if you were playing it as a parlor game with teammates.
In a stall that has a puzzle, you play a single player puzzle and depending on your rating you will give an hour of labor (need a badge on dub oceans) towards the creation of an item each time you play or if you have taken a job there you will recieve money depending on your ocean rank because the stall uses random (well, not random, but won't get into detail) labor hours from workers every hour towards an item. Not all stalls have puzzles, but that should be changing soon.
In the Inns, there are many parlor games to play. Poker, Swordfighting, Treasure Drop, Drinking and more. Some of these games you can play multiple people if you wish, while others it's one on one. I, personally, played poker most often, but I wasn't a bad drinker or swordfighter...
Now, puzzles aren't the only thing to the game that makes it fun. It's the fact that you can do many things besides fighting other pirates for PoE (Pieces of Eight, the currency) or play parlor games that makes it fun:
You can customize what your avatar looks like by buying clothes from a tailor stall or earning them through the Navy. Along with this is player housing. It is sadly instanced, but very customable and many different designs.
You can join a crew, which is like a guild, and rise through the ranks and make Officer or hire. A short note is that you have to be atleast an Officer of a crew to sail a ship. Each crew has a set of rules on promotions though, so it isn't always easy to get. If you don't like the idea of serving a captain, you can start your own crew when you have enough experience.
You can run a stall, where almost all the items in the game are created. However, you'll have to be willing to play the market often and sometimes deal with the economy (will go over the economy in a minute) which can be a pain. It also costs a nice chunk of change to start it and keep it going. If you like crafting and trading, this is differently a good idea to do.
Last thing to do is you could get into politics. Start a flag and take over an island to govern through war. Of course, this does require a lot of experience and requires you to have a good flag/crew. Through this, the world is not completely static and if you are a force to be reckoned with you could dominate many island and possibly change the ocean.
As with all games, there are a few problems:
The community isn't bad, depending on the ocean, but older oceans seem to hold more elitism while the newer oceans seem to have more of immature pirates. Dubloon oceans attract the free to play crowd because you don't have to actually pay anything unless you want to which often results in immature people, sadly.
With this, it's easier to get into crews and get high ranks on a dubloon ocean, but many crews are pretty horrible and don't even know how to sail, where in an elitist crew you'll make a lot of money but will rarely advance because you are not in the in-group.
On dubloon oceans, players pay real money to recieve the dubloons which is needed to buy items from stalls and the such (it's a sink and nobody will get these), but they can also sell it in game for PoE. This can be a good and bad thing. Problem is that there are a few pirates out there that have a nice big credit card and don't need to lift a finger to get a lot of PoE. This does have an effect on the economy and it can allow one person to easily own/run things without working for it. Hate it or love it, RMT.
And finally, ending this semi-long review, is the fact that most of the puzzles get boring after the 50th time doing them. They do increase in difficulty as you get higher ranking, but it's still the same puzzle. Of course, if you don't play the game for hours at a time and play here and there I'm sure that it wouldn't get to that stage for a while....
This was longer then I wanted it to be, but eh, I don't want to cut it anymore then I did.