Eamon Flack's production succeeds in elements but somehow doesn't entirely cohere. It's partially, I think, that the pre-show device (having the cast in generic white clothing meandering around the stage fooling around together) doesn't really tie into the rest of the show in a dramatic way - are they meant to be children or madmen, and how does this inform the show that happens afterwards? Alas, it doesn't quite inform anything - the white clothing shows up when the cast are playing minor characters occasionally, as does the child-like behavior, but it's not quite a big enough gesture to really hold the evening together.
Having said that, this is by no means a show that one should write off. Key among the performances is Keith Robinson, a onetime Belvoir stalwart whose health problems have kept him offstage for about a decade. His return is an absolute triumph - he's a more-than-usual fourth-wall breaker of a Feste (including recycling some old "Popular Mechanicals" jokes at the beginning of Act Two) and he hands singing duties over to Emele Ugavule (whose voice is strong and pure), but it works and makes him compelling. Peter Carroll seems born to play the angry puritan turned crazed lover Molvolio, and owns the role brilliantly, Anita Heigh builds nicely into the role of Olivia - her increasingly obsessive romanticism is delightful. John Howard is falling a little too comfortably into a standard "drunken cynical John Howard role" but he's good at it. Anthony Phelan has a good comedic presence as Sir Andrew, and Lucia Mastrantone has good frenetic busyness as Maria. Amber McMahon scores well as both FAbian and Sebastian (in particular she does great leg-comedy as Fabian attepting to get off a wall). Damien Ryan does not do a lot with the role of Orsino but there is not necessarily a lot to do with it, while Nikki Shiels is not the most interesting Viola I've ever seen but is personable and perfectly pleasant.
There are some staging highlights in here - especially the almost-music-video-ish "Come away death", but all in all this is a show that is more likeable than compelling. So I have to call this mixed. It's not bad, by any means, but it's not brilliant either.