So, the film rolls through it's basic setup pretty quickly - the Collins family come from England, help found a town and a fishing fleet and generally do well for themselves. After a brief dalliance, young Barnabas (Depp) breaks the heart of a serving girl who turns out to be a witch (Eva Green), which is a bad move compounded by him then falling in love for real with someone else. A quick curse later and Barnabas' new love is dead, and he's a Vampire, although he someone manages to sire some extensions to the family before being locked in a coffin for a couple of hundred years. Waking in 1972 he re-adopts his descendants and faces off with the witch again because, um....family, I guess?
Dark Shadow's big problem is that it really has no idea what sort of film it wants to be, and where it wants its characters to sit. Its not funny enough for a comedy and not scary enough for a horror film, and swings between trying to be both seemingly at random. The film it most reminds me of is Burtons own Sleepy Hollow, but where the earlier film was joyously gruesome, this latter attempt constantly backs away from letting the blood run in a way that would make it much more engaging. I can only surmise that this is from a desire to earn a PG-13 rating, but it hollows out the films horror elements rather badly, and so the humour don't come as a release.
It also doesn';t really know what its story is; a maze of subplots pulling away from what is (i guess) the primary tale of Barnabas, his reincarnated love, and immortal nemesis. We have subsplot with Helena Bonham Carter's shrink, for instance, which has literally no bearing on anything else in the story, and even the characters absence later in the movie is remarked upon with a shrug rather than worked into a plot point. Same for the woefully underwritten story involving the family's youngest child, and the less said about "I'm a werewolf, deal with it", the better.
All the said the cast give it their all, and a lot of individual scenes work pretty well. Burtons obsession with Goth Pantomime dressing is a great fit, and there are regular flashes of a better movie trying to escape. It leaves Dark Shadows as a bit of a mess; not as terrible as Alice in Wonderland, which is something to be said for it, but a long way from the interesting filmmaker that Burton used to be.