Short version: Hellboy II: The Golden Army stretches beyond the first film in both creepiness and humor, making for kind of an odd mix that manages to work in the end.
Screen Rant reviews Hellboy II
Hellboy II: The Golden Army is great, but like the first one, I don't think it's for everyone. The first Hellboy only earned $100MM worldwide, which does not exactly classify it as a (pardon the pun) monster hit. That's not to say it wasn't great (it was), it's just that the world of Hellboy is an odd combination of demons, humor, action and creepiness. Oh, and the hero is a demon.
Director Guillermo del Toro's fingerprints are all over this, right from the start of the film. We actually meet Hellboy as a, well, boy - and this gives John Hurt a chance to cameo as the adopted father of Hellboy, despite his having died in the first film. Seeing our big red buddy as a cute little child with big buck teeth was a bit weird, although he was very cute and wide-eyed.
Adding to the weird feeling at the start of the film was an animated sequence that gave us a visual of the bedtime story that Hurt was telling Hellboy - although the story consisted of humans, elves and trolls, the humans were portrayed as featureless wooden dolls. It was very interesting visually, but more than a bit strange. The story basically sets up the premise of the film, in which there was a huge war between men and the elves. The Elves were losing and had the trolls build them a golden, mechanical army of "70 times 70" soldiers - the soldiers obeyed whoever wore a golden crown and were emotionless killing machines.
Eventually the elf king feels remorse over all the death that has come by his orders and arranges a truce between the elves and mankind, which has held for many centuries. The prince of the elves was never satisfied with this and still lives today in shadow, awaiting the opportunity to once again destroy mankind. He has part of the crown, but it is in three pieces and he needs to acquire them all in order to re-animate the golden army.
When we are reintroduced to our intrepid heroes: Hellboy, Liz and Abe Sapien (this time voiced by Doug Jones, the actor behind the makeup) we see that things have progressed by big H and Liz as far as a romantic relationship, but things are not going well. Hellboy is stuck in his bachelor ways, and on top of that is desperate for their secret group to become public.