Calling this movie "a mess" could be seen as charitable, and certainly I'm a softer landing for the film's charms than a lot of people would be. I thoroughly enjoy a lot of The Lonely Island's previous output - both on and off SNL - and Andy Samberg's turn in Brooklyn 99 has won him a lot of good will in my book.
But the mockumentary style employed by the group's first movie foray doesn't feel used properly. Aside from inviting comparisons to This Is Spinal Tap - which will inevitably not work in Popstar's favour - it's implemented in a way that feels inconsistent, with no clear rules about where this documentary crew is supposed to be filming from. That said, the documentary style is justified by the insert interviews, with real musicians commenting on the career and music of the fictional Conner4Real, which offer some of the best gags in the film.
The music, too, is a mixed bag, but unlike their SNL and album tracks these songs are supposed to be bad. My favourite track, Finest Girl (Bin Laden Song), is borderline-offensive on the scale of Team America, but Popstar lacks the political position to give it teeth (for better or worse). Most of the songs get less than a verse and chorus to make their point - the only other song to make it into the film as more than a jingle is the deeply uncomfortable Equal Rights, though again its obvious textual shortcomings are excused by being a fake song by a fake artist making a point about homophobia.
The film's biggest stumbling block, however, is its lack of a clear point. Sure, it stumbles into a moral lesson for Conner by the end, but lacks a proper buildup. Conner's personality is at turns naive and childish, clear-headed and pragmatic, or entitled and overconfident - seemingly in whatever combination best suits the punchline to the scene in question. Taken individually, most of the sketches that make up the film are great, but they don't gel together and undermine some of the later scenes where we need to believe that Conner is an insulated narcissist for the emotional punches to land.
Even as a Lonely Island and Adam Samberg fan, I'm not sure I could recommend this film. It's the kind of entertaining curiosity I'd suggest catching on TV if you stumble across it, but it's unlikely it will ever end up on a regular ITV2 rotation.