They did dirty to the best part of the LN, they didn't introduce Rudy the Hunter who thought about using the Holy Hammer against Mammon, purified silver bullets to left him one eye blinded, used animal traps and fought like an animal trying to avenge the love of his life and died more a hero than the hero in turn.
Well at least the moms appeared sooner, Ceres wasn't as trashed as originally planned and the "I'm your father" scene was better developed. Guess you can't win them all.