Disclaimer: This is the first movie from the Underworld franchise that I've watched.
Given that I virtually have no idea and appreciation of the Underworld films prior to Underworld: Rise of the Lycans, I think the film does a decent job of laying down the mythological foundation of the franchise. Since the film is set in the distant past, it achieves two things: It was easy to explain the absence of Kate Beckinsale, the female lead for the first two films, and an excuse to replicate the scope and scale of the Lord of the Rings series.
Filling in the femme fatale role is Rhona Mitra, but does a rather weak job (She's no Kate Beckinsale). The story is middling, not good, but not great: the film focuses the rise of the Lycans (a hybrid race of werewolves and humans) from slavery from the vampires, as opposed to the Romeo & Juliet romantic angle between the Sonja (Mitra) and Lucian (played by Michael Sheen).
My main nitpick on the film is the very dark color palette, and a lot of the scenes happen at night, making it doubly hard to appreciate the violent and gory action scenes.
Underword: Rise of the Lycans makes me a little interested in renting or buying DVD's of the first two Underworld films, but over-all it's like the vampires and werewolves of Twilight placed in the era of Lord of the Rings.
Technorati: Underworld: Rise of the Lycans