I love roman movies and series.
I felt Atticus was by far the strongest character in the movie.
The fighting scenes were ok as well, especially Atticus finale fight.
However the rest of the movie seemed below what it could have been , in particular the volcano erupting took way too much of the movie, as if they were just too tempted for more action/cgi less back story.
The film is part Roman gladiator film, part disaster movie. It essentially shifts genres about halfway through.
I won't defend it as a great piece of filmmaking, but I've watched it two or three times and have come to appreciate it for the B-movie that it is. It's decent popcorn entertainment, with a likable lead in Kit Harington, a scenery-chewing villain brought to life by Kiefer Sutherland (of all people), a few decent battle scenes, and pretty good effects.