Stories of epic scopes for an actual premise should be told at epic lengths. 1 hr 36 mins just doesn't work for this film. Let me explain.
The plot and character development in this film feels like it moves at a rushed pace. Just as things feel like they are going to develop in actual plot depth and character depth, it is stopped. Suddenly, the plot is pushed ahead way too soon, as it doesn't develop into much plot-depth. And just when the character development begins, suddenly they decide to push the plot ahead too soon.
So, there really is not much characters to even really care for. The only character really developed worth any while is actually Eragon (of course) and Jeremy Irons' character, as he is the most interesting character in the film.
(Spoiler about an event in the film w/ Irons' character....)
Too bad he gets killed off, as his acting in this film was great -- despite the film not being so great. Irons owns this film. His character should've been the main character, personally....
As for Eragon himself, eh.....I don't know who this actor is, but his acting skills are definitely not strong enough for to command this role. He drops the ball, never commanding the role like he should. Plus, the Eragon character itself, at least in the movie, is not as interesting as Irons' character, either.