Twi-hards — the truly obsessed, and usually female, fans of the four-part vampire love story — found themselves bouncing and squealing at the stroke of midnight last night as “The Twilight Saga: New Moon” finally premiered nationwide. The film is the second installment of Stephenie Meyer’s outrageously popular series, and the first saga since the Harry Potter franchise to create such an obsessive commotion.

It has been almost a year to the day since “Twilight” first hit the big screen, creating a divide between the Team Edward and Team Jacob fanatics. Twi-hards have spent roughly 364 days anxiously anticipating the second installment of the saga, decorating their rooms with Edward Cullen posters and adorning themselves in Jacob Black T-shirts. Luckily for these fans, “New Moon” is sure to fulfill and satisfy their vampire voids.

“New Moon” proves itself an undoubted improvement from last year’s “Twilight” and fans can thank the switch from director Catherine Hardwicke (“Lords of Dogtown”) to Chris Weitz (“The Golden Compass”). Faced with perhaps the slowest plot of the four novels, Weitz compensates by adding exciting new elements of action and a richer use of color with refined cinematography.

The soundtrack of this film stands out as well. The exceptional compilation of songs from indie artists includes well-known bands Death Cab for Cutie and The Killers and emerging groups Sea Wolf, Grizzly Bear and Editors. The exact placement of the tracks in the film exemplifies the growth in the franchise as the edgier songs highlight twists in the plot, unlike the first film’s overuse of droning melodies.

The improved quality of the acting is a pleasant surprise for viewers who originally cringed at — or, for Twi-hards, chose to ignore — some painfully forced moments in the first film. Taylor Lautner especially shines onscreen as Jacob Black, a minor character in “Twilight” who becomes the focus of “New Moon.” Jacob forms the third point of a love triangle with Edward and Bella.

In this film, Jacob hits puberty in an unusual way — instead of awkward voice cracks and sudden growth spurts, he takes on a double-life as a werewolf in addition to a jaw-dropping physique. To keep the role, Lautner spent months in the gym and packed on 30 pounds of muscle, and his efforts certainly do not go unnoticed. The actor’s physical transformation from gangly boy to muscle-packed man obviously pleased female audience members, many of whom voiced their approval with girly shrieks. Weitz appeals to this target audience, giving Lautner plenty of shirtless screen time.

Unfortunately, Kristen Stewart’s banal acting is an utter foil to her castmate’s enhancement. Her undeniably simplistic portrayal of Bella, which barely slid by in “Twilight,” resumes in full force in this film.

Lacking the ability to convey emotions beyond bland uneasiness, Stewart fails to convincingly portray a heartbroken, emotionally crippled teenager. Stewart’s limits are particularly exposed in the plot-defining moment when Edward leaves her. In this incredibly traumatic scene, which is meant to drag Bella into a severe state of depression, Stewart fails to ignite even a small spark of genuine emotion.

Conversely, “New Moon” has distinctively wittier dialogue and more playful banter between characters — especially between members of the vampire clan. This sequel transcends beyond its simple romantic factors.

Bella’s father, Charlie Swan (Billy Burke, “Ladder 49”), and her best friend, Jessica (Anna Kendrick, “Elsewhere”), establish themselves as scene-stealers. With entertaining depictions of their characters and their use of comedic timing, the two actors flaunt their humorous lines, leaving viewers anxious for them to reappear onscreen.

In similar fashion to “Twilight,” “New Moon” struggles to develop a comfortable pace. The timing is exaggerated in all the wrong places; the defining scenes of the plot, like the epic birthday party scene that sends Edward running, are spit out in mere seconds, while awkward, less-important conversations eat up screen time and are awarded far too much attention.

Some scenes, including a flash-forward of Bella and Edward running through the forest in slow motion, are too cheesy to be particularly believable. The overwhelming awkwardness of the image strips it of any substantial meaning.

As a whole, “New Moon” is a major step up from the original “Twilight,” but both films still fail to stand on their own apart from the novels. This weakening factor makes the saga inferior to the fantasy phenomenon that is “Harry Potter,” because those films are, regardless of any previous knowledge, purely captivating.

True Twi-hards, though, will see — and probably memorize — the film by the end of the weekend. As for everyone else, the opportunity to see an angsty Pattinson and shirtless Lautner on the big screen will undeniably give audience members far more than their money’s worth.

— Contact Sara Hagey.