Film The Least Bad sequel
That title is probably the kindest verdict I can give the film, and that is a very long way from actually being, well, good.
The main problem with the film is essentially that it is completely derivative of the other films. With the possible exception of the female lead's science leanings there is not a single element that I can recall that is not a thinly veiled retread of something done before - when they bother veiling it at all. Zombie pirates, Jack's relationship with the protagonist duo, a (wince-inducing) cameo from an English rock star, I could probably hit the word limit on listing more examples.
There is also the question of Jack Sparrow. It almost seems impossible to think how popular, funny and fresh he felt five movies ago - even taking the off-screen... issues... with Johnny Depp out of the equation, the fact remains that the character's shtick has been running thinner and thinner with every movie, and feels incredibly tired by now - all the more so given the complete lack of new ideas the movie brings.
It's not all bad however - the plot moves along briskly enough that the runtime doesn't drag on like previous films did, and most of the elements copied are at least the successful ones; their old but they did work, and for the most part still do. Should this end up being the last POTC film, it wrapped up pretty much every plot thread and satisfactorily so at that.
All in all, there is probably one particular scene that serves as an apt summation of the entire film when a zombie shark jumps over a boat. Perhaps not true to the strictest definition of 'shark jumping' but certainly close enough to suggest that this franchise has run it's course.
Film The Perfunctory Pirate
There's a scene about half an hour into Pirates of the Caribbean 5: Dead Men Tell No Tales, where an innocent ship out to sea gets devoured whole by a new monster. It looks exactly like a scene from Pirates of the Caribbean 2: Deadman's Chest, wherein an innocent ship out to sea gets devoured whole by a new monster. Thus is the nature of Dead Men, recycling the basic imagery, concepts, and even parts of the title from previous Pirates of the Caribbean movies.
The plot to Dead Men, for what it's worth, is a quest to find Poseidon's Trident. It grants power over the sea, and also the ability to free Will Turner from his duties as skipper of the haunted ship, the Flying Dutchman. This quest is being carried out by Will's own son, a mythology buff, who you'll forget about every time he's not on screen. Carina is also helping. She's a lady astronomer accused of witchcraft, perplexing in an era where people had stopped believing in witches, yet also for a movie setting where there are actual witches that look nothing like scientists. Carina is probably the most original introduction to the franchise, yet spends most of the movie rolling her eyes, making terrible banter with Will Jr, and getting mistaken for a whore. As for why Will Turner himself isn't helping, despite having a magic, unstoppable killer ship of his own, is an interesting question the movie skips over. Thinking about it, this is a franchise which said Will's curse meant he and Elizabeth could only meet on land once every ten years, but doesn't say why Elizabeth won't just ride on his boat the entire time; Pirates never worked hard on filling in the blatant plot holes.
Everything about Dead Men feels perfunctory in its inclusion. You have to have your undead pirates. You have a villain with a personal grudge against Jack Sparrow. You have to have a big monster ship. You have to have a magical treasure artefact. You have to have Johnny Depp acting drunk again. Let's throw in a rock star cameo, even though we did that exact same joke already. Javier Bardem plays an utterly forgettable villain who's entire deal is, get this, he really doesn't like pirates. Wow, what an original topic for a Pirates of the Caribbean movie! I see they're still pretending that pirates are the victims, and not, you know, murderous, thieving sea rapists.
It feels like even the movie knows its going through the motions. Jack has none of the presence he once had, with Johnny Depp reciting the joke dialogue in halfhearted wheezes. "that's my stern!" says Carina, referring to her arse. The movie repeats this joke several times, as though it was hilarious the first time around. There is none of the wit or the heart of the first film, and even the sequels, whilst being rubbish in their own right, at least made an effort to do something new. This is a tired franchise that, unlike its villains, just needs to stay dead.