First we have a review from the Filmschoolrejects site here. The review states that the film "serious lack of structure and information" noting that you have to make a guess as to where the scenes depicted fit into the Gorillaz timeline. During parts of the film Gorillaz art flashes up on the "screen at an epileptic rate." Various stages in the recording of Gorillaz songs are shown, as is a behind-the-scenes look at how Gorillaz perform in concert behind the screens. Damon Albarn's hate of the politics and 'the dog and pony show' surrounding album releases is said to be apparent throughout. The film is awarded a grade D by the site.
The blog Movie Digs has a review here. Complaining that the audio is poor the review states that much of the speaking is mumbled except for the curses (!). Like the review above, the behind-the-scenes look at recording a Gorillaz song was praised, but the reviewer felt not enough was shown of the development of the Gorillaz animation.
The site /film gives Bananaz a rating of 6.5 out of 10 (read the review here ), calling it a "kind of insular, for-fans-only documentary that means a limited theatrical run, if any, and a somewhat appreciative audience on DVD". In a "loose, unstructured, and ultimately self-indulgent" style, we get to the Gorillaz creators hang out, goof off, recover from benders, do sound checks, do interviews, and perform. Damon is shown at one point being sick because of stage fright nerves. No complete Gorillaz tracks are played in the film, a maximum of one and a half minutes of a track is played before the next cut. But, according to the reviewer "most of these scenes are nowhere near as fascinating or compelling as Levy thinks they are." For fans however, it sounds like every minute will be fascinating.
Another blogger, THE Andrea writes here, " I think I now know less about the Gorillaz than before the movie. I’m just so damn confused. I could rarely understand anything that was being said. When I could understand, I just never understood what the hell they were even talking about. Other than a slight indication of chronology due to when albums were released and touring, I have no idea. I just have no idea. If this review has confused you. Join the friggin’ club. 3 out of 10".
Tunaflix has a very positive review of the film here. The review says Bananaz is an "impressionist piece than a straight-up “These are the facts” documentary" which "manage[s] to mirror the aesthetic that makes the Gorillaz so interesting". The review concludes that "Definitely worth seeking out for fans of the band." and reveals that Director Ceri Levy was onhand for a Q&A session after the premiere screening.
Firstshowing.net has a 5/10 review of the film here. Noting that "the animated band is leaps and bounds more interesting than Hewlett or Albarn alone.", the review concludes that "This turned out to be a great sell to the hardcore fans of Gorillaz, but I doubt anyone else would be interested in it". However the reviewer felt that "Damon Albarn luckily turned out to have a unique personality that came through some of the time.".
Austin360.com was more upbeat, summarising the movie as a "for-fans music doc both in its casual shooting approach (so “fly on the wall” that the filmmaker doesn’t seem to care if we understand everything being said) and in attitude (we’re expected to admire the main players enough that their juvenile antics go unchecked)". But there's "just enough pop-culture flash that it holds some appeal even for newcomers.". Read the full review here.