The movie presents its plot like a ridiculous gamble, and keeps pulling it off, somehow managing to justify its existence.

By the climax all concerns have gone out the window, as Vigalondo delivers an operatic finale that feels both earned and genuinely cathartic. For better and worse, you won't have seen a movie like Colossal before, and you won't again. And that, in itself, is a strong recommendation.

In substance, it might be Vigalondo’s most ambitious film to date. And while there’s a sense at times of his uncertainty in fully committing to the ideas on the page, in the moments when the conceptual component of “Colossal” is fully embraced, the results are truly chilling.

Vigalondo has a top-notch conceit that unfortunately loses its way when buckling under the weight of the middle third’s anything goes antics. Thankfully, however, the climax prevails in its thematic resonance, moral quandary, and righteous hope.

Colossal possesses some real depth in its acting and its description of human relationships, it's just a shame that when it sinks a few beers and gets up to do the monster mash: things get a little too silly.