The film contains ten scowls, four glowers, seven leers, fourteen grimaces, and numerous sneers; there's rancid fog, rivers of blood, a hellish below-ground furnace, a number of charnel scenes, and - worst of all - Broadway showtunes. The art and set design and costumes and look is fabulous, but the general tone is black. (Not entirely true: some of the characters have their grey moments, too).
The typical scene goes something like this: Sweeney Todd philosophically sings a mournful little song under a black sky while cheerlessly slitting the throat of his latest, understandably dour-faced, customer, perhaps reflecting gloomfully upon the wicked state of the world.
Apart from that, it's all a bit of a downer.
In unrelated news, my hair's getting a bit long, but I'm thinking twice about having a haircut...