Downsizing is the new film from Alexander Payne, the writer/director behind About Schmidt and Sideways. Staring Matt Damon in the lead role of Paul Safranek, the story is built around a groundbreaking new procedure designed to combat over population, which allows people to permanently shrink themselves to five inches tall.

With money equating to much more in the small world, Safranek, a struggling occupational therapist, undertakes the procedure to give himself a better life, but things don’t go completely to plan and he soon finds himself alone in a tiny, unfamiliar world.

With Kristen Wiig staring as his wife and Christoph Waltz impressing as his overbearing new neighbour, the first half of the film is entertaining and engaging. Matt Damon’s likeable therapist, is easy to warm to. His excitement at the opportunities downsizing creates are clear to see and it’s hard not to feel for him as his well made plans begin to crumble.

Unfortunately, after setting up a number of interesting concepts, the film falls down in the second half. Taking on a completely different tone as the story moves into vastly different territory.

Embarking on an environmental quest with his neighbours, Vietnamese cleaner (Hong Chau) Safranek’s story meanders away from the themes of the first half and the miniature world that offered so much is left mostly unexplored.

Hong Chau’s turn as refugee turned cleaner, Ngoc Lan Tran is the second half’s highlight. Her delivery of the broken English accent is endearing and at times laugh out loud funny.

It’s clear Payne’s intention is to address a number of subjects, including overcrowding, financial struggles and climate change but he never finds a way to gel them together successfully and what’s left is a film of two very different, totally contradicting halves.

There is still much to like about Downsizing, particularly in the early stages and the fact that Payne is such an ambitious filmmaker is to be admired, however his film suffers from an identity crisis and many viewers will find themselves losing patience as it drags into the latter stages of its two and a quarter hour runtime.

By the end, cinema goers will be left wondering what happened to the other movie they were watching as the film’s early promise gives way to something much less satisfying.