1. "Paul" has one ingenious idea, one that's more clever than necessarily funny: What if every aspect of science fiction over the last 50 years actually came from the mind of an alien who crash landed at Area 51? This would make this alien truly Americanized, not only a rabid consumer of geek culture, but in fact its creator. It's a smart twist on the "wacky cute alien sidekick" character; our alien buddy doesn't just quote "Predator," he knows the guy it's based on. When Hollywood's looking for ideas, they just call him, safely ensconsed in a government-operated secret bunker; when Steven Spielberg wants to figure out how E.T. should look, he calls him. Spielberg actually makes an audio cameo in "Paul," and it's the movie's biggest laugh. Which is a problem.
2. "Paul" has an impressive amount of comedic talent on hand: Jason Bateman, Kristen Wiig, Jane Lynch, Jeffrey Tambor, Bill Hader, the voice of Seth Rogen and the "Shaun of the Dead" team of Simon Pegg and Nick Frost, who both co-wrote the screenplay. But the film suffers from a bad case of Rogen-itis: It has a good idea but is a little too lazy/stoned to do much with it. Essentially, the movie's main joke is the joke. Our two heroes, played by Pegg and Frost, are science-fiction nerds from England who plan a road trip to America's famous sci-fi landmarks, from Roswell to Area 51 to wherever Kirk and Spock battled each other on "Star Trek." Along the way, they meet Paul, an alien who has escaped from his prison in order to, of course, phone home. Paul has the voice, cadence and personality (if not the figure) of Rogen, so of course this alien speed references comic book lore, curses a lot and smokes a lot of pot. The notion of an alien who acts like Seth Rogen is a funny one. It's just a notion, though.
3. This is a road movie, so the movie just sort of shambles from one place to another, picking up characters and discarding them with little discretion. Paul and the boys are being chased by Bateman, and that's the plot. The gang gets stoned together, discusses old alien movies together, and becomes best palsies. This would be just fine if it were funnier, but the movie is more content to reference geek culture than to do much with it. It never decides if it's spoofing road/alien movies or being a sincere one. (Again, another symptom of Rogan-itis.) The reason Pegg and Frost are so likable is that they seem like real people placed in fantastical situations. Here, they're ciphers at the service of their movie, excuses to hop to another setpiece rather than breathing human beings. They're citing the Comic-Con influences rather than having fun with them. It's a bad sign when one of your major characterizations involves what T-shirts your characters wear; Wiig's Jesus freak wears an anti-evolution shirt, Pegg proudly bears his "The Empire Strikes Back" garb. These are gloms to a Comic-Con audience -- our characters actually visit Comic-Con at one point, to little comedic effect --- rather than a satire of them. This movie wants its little blue Matrix pill, and to eat it too.
4. Wiig's character is particularly problematic; this is not a performance I suspect she'll ultimately be too proud of. She is a one-eyed evangelical yokel under the thumb of her domineering father, and the movie uses her as the butt of several tired, cheap jokes about religion. By the time the character turns to the sins of the flesh by randomly tossing out non-sequitur curse words, you'll be ready for her to just go away. Bateman, Hader, Lynch and Tambor are given nothing to do, and Pegg and Frost are almost wasted in their own movie as well. But how funny you find "Paul" depends on how "outrageous" you find the alien character Paul on the whole. If it cracks you up to see him moon strangers, or get in a bar fight, or call everyone he meets "dude," you'll love the film. But the movie outsmarts itself; it tries to be a Wacky Alien Comedy that's not like every other Wacky Alien Comedy. It does this simply by upping the vulgarity quotient; I lost count of the number of times Paul burps in this movie. Pegg, Frost and Rogen are funnier than this; I can't tell whether they're making concessions to a wide American audience or just being lazy. Either way, it's disconcerting to see such funny people consistently doing such unfunny things. Though it is fun to watch Blythe Danner smoke weed, I will confess.
5. In my review of "Star Trek" a couple of years ago, I lamented the mainstreaming and scrubbing of a once proud, but underground, geek culture. (Patton Oswalt made a similar point, in a more entertaining fashion, in his book "Zombie Spaceship Wasteland.") "Paul" is less a valentine to that culture than a usurping of it. This is a movie for you, you nerds, it proudly exclaims from the opening scenes, and then goes about being exactly the type of movie geek culture would once reject. It's just a silly comedy, with a few funny moments, that doesn't try too hard. It doesn't take itself even the slightest bit seriously. But the signature trait of geeks is that they view this stuff with the utmost seriousness. "Paul" wants to speed-reference science-fiction culture without reflecting it. These guys would kicked out of any usenet group or alt.startrek forum. This is a nerd movie made by n00bs.