After the middling David Brent: Life On The Road a few weeks ago, we have another comedy-mockumentary-musical, this time with The Lonely Island. Their songs maybe funny, but is the band able to fill out an entire movie length? Let’s find out.

Popstar: Never Stop Never Stopping stars Andy Samberg, Akiva Schaffer, Jorma Taccone and Tim Meadows and is directed by Schaffer and Taccone. The film follows pop singer Conner4Real (Samberg) who tries to make a comeback with his old boyband, “Skill Boyz”.

Every comedy-mockumentary-musical (which for some reason is a really big market) is obviously going to be compared to Spinal Tap, basically the ground zero for all three of the genres at play. Popstar is nowhere near the leagues of Spinal Tap, but nothing ever is. It’s a disservice to both films to try and compare, so we’ll just have to look at Popstar on its own merits.

The Lonely Island are known for their comedy songs, and they have some excellent ones in Popstar. Songs about the assassination of Bin Laden (used as a metaphor for sex), gay rights (which ends up just being a mash up of random words) and an entire song about being humble, the satirical lyrics and crazy music videos are good for couple of minutes. This is where Popstar shines, but we only get a few songs and videos at most.

The rest of the jokes are a mix of great and abysmal. Some corkers, like an extended “incident” at the Anne Frank Museum (a not-so subtle dig at a certain star), breaking celebrity news by CMZ (digging at TMZ, and led fabulously by Will Arnett) or an over-the-top proposal, complete with wolves, by Conner4Real to his trophy girlfriend, are good set-pieces, but the rest is just screaming and random sequences of “chaos”. If it wasn’t for the bared penises, breasts and the occasional swear word, it could almost be at home on the Disney Channel, inane nonsense for tweens.

The film has a huge cast list, with several musicians, such as Ringo Starr, A$AP Rocky, Mariah Carey, Carrie Underwood and 50 Cent, as well as other famous people like Simon Cowell, Jimmy Fallon and Martin Sheen. Most are just kept to talking-head interviews per the documentary-style of the film, but since most are poking fun at themselves or the music business, I am okay with so many stars turning up. It’s better than Zoolander 2, which shoved stars in despite them having nothing to do with the world of fashion or the story.

The film is only 86 minutes long, pretty short, but the lacklustre story makes it seem far longer. The documentary style is dropped quite early on, leaving us with a rather desperate and plodding orthodox style, which isn’t interesting. We have no investment in the characters, we are meant to be laughing at them, not with them, so when the film tries to be a drama where we sympathise with the main character, it grinds to a halt.

It’s sad, I was looking forward to Popstar, but it seems The Lonely Island work better in short form. Cut it down to an hour, you would have a funny TV film. Cut it down even further, you might get a vlog series out of it. It could work any other way, just not in the cinema. You might get some more enjoyment out of it if you are a diehard Lonely Island fan, but for the rest of us, it’s just passable.

Score: 6/10 Some funny moments, but nothing essential.