A great concept.

The first half which attempts to show the breakdown of society is excellently handled. Very funny and absurd.

While the love story works in parts it never feels fully fleshed out. When the second half of the film focuses almost entirely on this the change of tone is noticable. There's barely a single laugh.

The cameos are occasionally distracting but the central performances are both very good (despite Keira's character being lumbered with that most achingly hipsterish of Hollywood quirks: she listens to old music but only on vinyl).

Some fine moments but the tonal lurch is too much.