I had never heard of Hellboy before the movie, so my opinion is based on just a movie, not preconcieved notions of what I should have been expecting.
Bottom line: I thought the movie was entertaining and worth seeing. Would I see it again? Nah. The special effects were pretty cool, the acting was fine. Character development? I thought that might have been a little lacking, but I'll just assume this was meant to be an action flick. There are a few romance scenes which drag ass... Probably mean more to the comic-reading crowd than the know-nothing viewer.
I felt that about halfway in to the film, it stopped getting deeper into the characters and the momentum or tension of the movie didn't raise anymore. Sure it didn't drop off... but it just flatlined at like 80% instead of ramping up to a good climax.
So basically I thought the movie started out awesome and fast, but somewhere in the middle it lost its way and ended up mediocre. Perhaps your best bet is to watch the first half, and then leave while your blood is still pumping and make up your own ending
