Nathaniel Graham’s review published on Letterboxd:
Competently made if not much more, Room relies heavily on its undoubtedly compelling subject matter for most of its draw. Perhaps most interesting is the quantity of issues and themes related to trauma that it raises. While it presents these effectively, the film doesn't dive deep enough into any one of them to deliver anything particularly profound.
That said, Room does leave you with an overall sense of the scale of emotional and psychological damage that traumatic events can have - and does orient the audience within child protagonist Jack's perspective in surprising ways. For example, I was initially a bit baffled by the choice to shoot a film about being caged in a single room in an ultra wide aspect ratio - but of course, from Jack's perspective, Room is the whole world.