On the face of it, this seems like a perfect fit for this kind of festival: a modern dress, abridged version of a Shakespeare comedy with an onstage rock band performed by a company of comedians, the latter idea having worked spectacularly well many times in Edinburgh.
Liam Williams's production focuses very much on the laughs and the drinking—it is rare to see a character on stage without a can of lager in his or her hand. This is fine for the drinking comic characters, especially Toby Belch, Andrew Aguecheek and Maria, but it makes some of the others with a serious side into superficial comic types.
Malvolio becomes just a ridiculous character and nothing else. His taunting isn't very effective or justified, nor is his final retort, which doesn't have much of a comic effect or a serious resonance. Orsino is turned into a giddy, lovesick schoolboy. Aguecheek has a thin, comic character that works fine, and Viola is actually very good for most of the time, almost single-handedly holding it all together, although Olivia has some good moments as well.
The main issue is that it is all a bit messy—not the aesthetic concept of litter all over the stage but the implementation of that concept, which is rather ramshackle and, it seems, under-rehearsed. If the performers are very good, they can respond to lost lines, wrong entrances and other mistakes within the casual style of the piece and make something good out of them, but none of this is made to work well here.
The concept is nothing new, the storytelling is unclear and the comedy isn't slick enough to be as funny as it is trying to be, so it certainly doesn't represent the best that this festival has to offer.