If one thing defines cinema in 2011, it’s alien movies. From “Super 8” and “Battle: Los Angeles” to lighter fare such as “Paul,” it’s been difficult to hit a multiplex without seeing some sort of interplanetary entertainment option. “Cowboys & Aliens” is the last big blockbuster of summer, and it’s not even the only alien movie opening this weekend, but its fresh twist on the genre makes it an entertaining ride.

Even though the film’s ad campaign touts it as blending sci-fi and Western elements, it starts off as a mystery. Jake (Daniel Craig) wakes up in the desert with a bizarre bracelet attached to his wrist and no memory of how it (or he) got there. He rides into the nearest town and quickly bumps up against Percy Dolarhyde (Paul Dano), unaware that Percy’s father (Harrison Ford) is a powerful cattle baron whose very name inspires fear in the local townspeople.

The film’s first act is by far its best, staged with all the tropes of a traditional Western. Director Jon Favreau nails the pace, letting an intense slow burn guide the opening scenes. He showcases beautiful, sprawling landscapes and dusty gunfights with a flair that would make John Ford proud. Also great is Dano, whose absolutely revolting character gets big laughs as Craig humiliates him time and time again.

And then the aliens attack, and the film begins to sputter. The first alien attack scene is effective and tense, but it’s also dark to the point of being distracting. Just before the aliens attack, the screen is so dim that it’s nearly impossible to see what’s going on, something that most of the film’s nighttime scenes suffer from. The film also makes the mistake of sidelining a good chunk of the supporting cast after this attack scene, taking Dano out of the equation, as well as Keith Carradine’s intriguing sheriff and a few others — all of them vital parts of what’s made the movie work so far.

Once the cowboys go tracking down the aliens who have kidnapped their townspeople, the film slowly catches up with its forward momentum. One of the main problems with this middle section is Harrison Ford’s character. Ford is, as always, simply awesome and gives an energized, hungry performance that holds up a half-baked character. His ruthless cattle baron never quite inspires the terror in the audience as he does in the characters, and his inevitable redemption arc is nothing short of forced. It’s as if the film’s five (!) credited screenwriters knew he had to start the film as a gruff bastard and end it as a slightly less gruff town leader but decided to let Ford fill in the blanks.

All of the film’s acting is solid, even if the character work isn’t. Craig is a hero through and through, instilling his character with a confidence that carries him even when he has no memories whatsoever. The film’s only real character is Sam Rockwell’s Doc, whose wife is kidnapped in the alien attack. At this point in his career, Rockwell can pretty much do no wrong, and he quietly steals the show from seasoned vets given much more material to work with, even getting the film’s most cheer-worthy moment.

Where the character work stumbles, Favreau picks up the slack by keeping the film moving. His aliens aren’t exactly distinguishable from the many other extraterrestrials that have graced multiplex screens this year, but there’s a few delightfully gross details that redeem them. Favreau also knows how to make his creatures menacing, casting them as fast, brutal conquerors that never run out of ways to kill you, brought to life by near-seamless visual effects.

“Cowboys & Aliens” gets a lot right. From the cowboy iconography to the thrilling action sequences, Favreau’s passion for the project is clear throughout, and that’s enough to forgive some shoddy character work and the occasional slow stretch. Fans of Westerns will find plenty to like here, as will sci-fi fans, but the real treat is watching Ford truly acting again. One can only hope he continues to give such clearly enthusiastic performances, hopefully with better written scripts in the future. And Ford isn’t even the strongest part of a stacked ensemble that helps make “Cowboys & Aliens” an enjoyable close to the summer movie season.

Printed on Thursday, July 28, 2011 as: Western crosses sci-fi in 'Cowboys & Aliens'