“A Million Ways to Die in the West” opens Friday at Point, Eastgate, Star Cinema and Sundance. R, 1:56, two and a half stars out of four.

“I’m not a hero,” Albert Stark (Seth MacFarlane) says at one point in “A Million Ways to Die in the West.” “I’m the guy in the crowd who makes fun of the hero’s shirt.”

Nailed it in one, Seth. “West” is at its best when MacFarlane, in his first lead acting role after creating shows like “Family Guy” and the movie “Ted,” has his character standing on the sidelines, riffing. The central joke of MacFarlane’s Western spoof (which he also directed, co-wrote and produced) is that Albert is a hapless sheep farmer who hates the Old West, and the best parts of the film are Albert’s hilariously foul-mouthed rants on how lethal everything is around him, from rattlesnakes to cholera to frontier doctors.

It’s when Albert (and MacFarlane) has to strap on the holster of a leading man that “West” falters. Looking like the Big Boy mascot if he put down the burger and joined a frat, MacFarlane isn’t a bad actor, but he just can’t go toe-to-toe with the likes of Liam Neeson or Charlize Theron. Parts of “West” look like those old Oscar intros where Billy Crystal would be spliced into actual movies.

Albert is the coward of the county in 1882 Arizona; after he pleads his way out of a gunfight, his girlfriend Louise (Amanda Seyfriend) dumps him for the dandified owner of the local “mustachery” (Neil Patrick Harris, scene-stealer extraordinaire). In a funk, Albert prepares to vamoose for San Francisco, but pauses when a mysterious stranger, Anna (Charlize Theron) comes to town. Anna takes a shine to Albert, inexplicably, and starts hanging around with him. She’s a Manic Pixie Dream Outlaw.

What Albert doesn’t know is she’s also the wife of a vicious gunslinger named Clinch (Liam Neeson) who will eventually come to town to claim what’s his. But until then, “West” just kinds of moseys along for its two-hour running time, content to leave plenty of room for MacFarlane’s digressions, gross-out jokes, and a drawn-out subplot involving a virginal suitor (Giovanni Ribisi) and his amour (Sarah Silverman), who also happens to be the town prostitute.

Some of the jokes hit, some of the jokes miss, and some of the jokes hit and then linger way too long. While even MacFarlane wouldn’t dare to compare his film to Mel Brooks’ classic “Blazing Saddles,” he goes for the same mix of the silly and satiric; a fart joke here, a wry comment on the treatment of African-Americans in the Old West there. While pop-culture references are MacFarlane’s forte, he’s limited by the time frame to just one ’80s reference (but it is the best joke in the film.)

Where “West” gets lost is when MacFarlane and Theron try to generate some chemistry together — Theron is so lived-in and natural in her role that she can’t help but show up MacFarlane on camera. And while MacFarlane can do quick visual gags (and the film actually has a picturesque, John Ford quality in its Western landscapes), he can’t shoot and edit an action scene to save his life. A chase on horseback feels needlessly drawn out and confusing, while the climactic gunfight is the epitome of anticlimactic.

“Ted” worked because, beyond the hooker jokes and “Flash Gordon” references (which were funny, no doubt about it), the film had something to say about the changing nature of male friendship. The fact that it had to say it about Mark Wahlberg and a talking bear only made it funnier. Here, it’s just a spoof, a series of gags that might draw a laugh, or might not, and either way end up evaporating in the dust.