The Star Wars movies are essentially composed of the following:
1 Fight Scenes
2 Clumsy Romance
3 High-Speed Chases
4 Questionable Acting/Writing
5 Freak Shows
6 Talk of Destiny
Hellboy II unproves on this formula by replacing "high-speed chases" with "relatively-low-speed chases". This isn't to say that Hellboy II is a Star Wars movie, but the comparison was impossible to avoid because it's not very inaccurate.
From the top.
Fight Scenes - there are a lot of them. Essentially, the movie would be about 14 minutes long if all the action was removed, and those 14 minutes would consist almost entirely of Howdy Doody and karaoke. The fights are pretty cool in general, but the number of them make this very much an action movie. No time for charming character moments, no time for build-up or anticipation, no time for much of anything besides killing monsters into pieces.
The original Hellboy, I thought, struck a pretty good balance between action and inaction. There was time for things to happen, and there was time to reflect and exhale and nurture a buddy-movie and an "I like you because you're different like me" romance all while gradually bringing the main story to its climax.
Even Star Wars showed a few minutes of briefing before the Death Star battle to give it some weight. Hellboy II would have played a 5 second sound byte explaining what the objective was as the pilots were already fighting. And there would be no fewer than 2 Death Stars.
Clumsy Romance - The original movie's romance was awkward because its male hero was awkward. To be sure, this film's lover is awkward as a character too, but the real problem is that this film keeps most of his exchanges with his beloved on a telepathic level, hidden from the audience. If the fight sequences followed the same laws as the romance subplot, both combatants would begin with a lingering high-five that would allow them to decide the outcome of the fight without actually showing us anything. We'd just have to take their word that the fight was amazing.
Relatively-Low-Speed Chases - Maybe a subset of the fight scene in that they occur in between them. Not much else to say. People run after each other and they're not in speeder bikes or pod racers.
Questionable Acting/Writing - If Jeffrey Tambor ad-libbed all his lines, then he needs to be more closely scripted, and if he was following a script then god help us. Also, Ron Perlman needs a new fake laugh along with more/better rapport with his enemies. The sense of humor from the first movie was all but absent in this film, and although the acting wasn't perfect in either film, only the second contained scenes that made me want to look away because I was taught not to stare at people who are embarrassing themselves.
Freak Shows - You know when Luke and Obi-Wan enter the cantina and Lucas shows us around the bar so we get a chance to appreciate all the crazy masks ILM made? Not necessarily a bad thing, but when the movie is short on time because of all the fighting, it doesn't make a lot of sense to blow so much footage on a troll market that appears on film more like the Disney Land ride version of a troll market. On the plus side, a lot of the monster designs are pretty rad, and I do dig the freaks that come out of del Toro movies, and some of the freaks even move the plot along rather than drag it to a near halt, but this movie's cantina scene is rather weak.
Talk of Destiny - This is actually a hook that makes me enjoy Hellboy. The nature/nurture experiment that's going on is something I like to see, so I was rather disappointed when it was relegated to a couple of quips (including a god-damned "we are not so different, you and I" from the villain) and a monologue.
In short, Hellboy II spent so much time fighting and looking at monsters that it all but discarded everything that made the first movie funny or charming or interesting. I honestly don't care if I ever see Hellboy II again.