It's not necessary to mention the terrible use of CG (most of which could have been done with cheaper, more realistic non computer effects), because that's not really where this movie can use improvement.
While the acting is mostly good, the script is very weak. Character interactions are awkward. Their relationship seem forced, like there doesn't really look like there's enough motivation for them to stay together. The fighting scenes are really badly coordinated. With that same group and just a bit of tactics, victory would come easy (at least to enemies shown) but instead everyone fights like if they were drunk or disabled somehow; so whenever the heroes are defeated, being in good condition, it is not believable. Also, all heroes are unremarkable: the warrior is not a great fighter, the wizard cast magic sparingly or waits the worst moments to do so, the "thief" is not really stealthy or that quick on the feet, and the priest has no real divine magic or combat power (despite "being trained in combat", see the first part).
Also the name/title of the enemy seemed like inspired from a video game, thus awkward and forced... the ending felt forced as well.
In the end, unless they improve script and character development and interaction, not even "Hercules" can save this movie series...
