This is the second Lego game I've played, the first being Lego Indiana Jones (Xbox 360). If you are familiar with the series, then it's probably how you would expect it to play out.
In terms of story, there are short cut-scenes but you really need to be familiar with the source material to understand the plot due to the brevity or lack of speech. Graphically, it is good although the 3D effect is so weak it is barely noticeable
There are 16 levels; 4 per film. In each level, you destroy objects, construct others and use your character's abilities to progress through the levels. When you play in story mode, parts of the level will be inaccessible to you due to the characters that you have. Once completed, you can revisit the level in Free Play mode which gives you more characters and thus giving you you access to all abilities. As well as the studs which act as currency, there are special coins to collect, ships in bottles, and a red block. The ships and coins are simply collectables, but the red block gives you access to the 'cheats'.
Once the cheats are unlocked, they can be purchased using the studs you have collected. These are very pricey, but if you save up for the stud multipliers first, you can rack up a large stockpile by using the X8, X6, X4, and X2 multipliers, which then can be used to unlock the rest of them. Other cheats help make the game easier/smoother to play such as the Invincibility, Fast Build, or the Stud Magnet, and then there's the cosmetic changes such as the Banana Sword, Big Head or Ghost Pirate.
The game is very simplistic and straight-forward so you should never be stuck. Obviously the game is aimed at the younger audience but the Lego charm really boosts your enjoyment of the game. You never really need to think in the game. When you see something you can interact with, if you have a suitable character in your party, he will flash on the touch-screen. It's just a case of wandering around and interacting with everything you can in order to progress. Jack's compass can be used to direct you to buried treasure. Ranged weapons can shoot targets. Characters who duel wield swords are used to scale Lego Walls. Blacksmith characters carry hammers used to construct certain objects. Some characters carry spades to dig up objects. Grappling hooks are used to climb/create tightropes/pull objects down. Dutchmen crew members use coral patches to travel and use lanterns to remove living coral. Cursed Barbossa crew can use moonlight to gain super strength. Mystic characters can move or conjure objects. Pets like monkey, parrot, dog, can fetch items and fit into small spaces.
There's not much combat, but that's a case of repeatedly hitting the attack button. There are also more important fights in the story which make use of quick-time-events, although you have quite a large window to input the command and you only need to get 2/3 correct to be successful. What should have added more excitement ends up being boring and slows the game's pace further. It would have been nice to have the option to tweak the difficulty to add more of a challenge.
There's a lot of grinding to be done during. After completing the game, I had just over 500,000 studs but the X4 multiplier costs 600,000 so I had to replay about 4 levels to raise the funds. It's a case of destroying everything you see and mopping up the studs. It's quite a strange system that pretty much requires you to purchased these multipliers, because I'd imagine kids would rush into purchasing an unlockable character or a cosmetic cheat and then struggle to raise funds to unlock everything else.
If you are looking for a challenging game, then you need to look elsewhere. This game is aimed at those that are looking for a simple, casual game to pass the time.