Mortal plods along for most of its running time with the occasional helicopter chase scene and plenty of CGI fulminology: But ultimately Ovredal's not-so-deep-dive into Norwegian mythos is a too-obvious let down.

Yet another dreary entry in the overly serious superhero genre, where brooding and brown cinematography add a false veneer of importance to the proceedings.

Øvredal's lopsided sense of humor has deserted him entirely: The sillier the story gets, the more glumly and earnestly the film trudges through it.

...slow-moving and palpably padded-out...