I am supposed to absolutely love Lenny Abrahamson’s Room, the high-concept art film of the year. I am supposed to be moved by it and, well, shattered by the experience. I am also prepared for some hard-core vilification because I am not. Truthfully, the best I got out of Room was intermittent admiration, which was also my response to Abrahamson’s last film, Frank (2014), though I liked it better.

Room is not a film that you’re supposed to “like,” though some seem to find it heart-warming. It’s the cinematic equivalent of taking nasty medicine that will cure you of what ails you. That said, all that nastiness is redeemed, in part, by one nicely sustained, if not wholly believable, suspense sequence in the middle of the film. However, it’s important to point out that Room is not a bad film. But, then again, it’s not the deep-dish masterpiece it’s been painted as by critics.

The story — adapted from Emma Donoghue’s novel — concerns a young woman named Newsom (mostly called Ma, and played by Brie Larson), who was kidnapped at the age of 17 and imprisoned in the title room by a man she calls Old Nick (Sean Bridgers). Two years into her ordeal, she bore her captor a son, Jack (Jacob Tremblay), who is celebrating his fifth birthday when the film opens. Since the story (at least in the book) is told entirely from Jack’s point of view, the background of it all is something we have to pick up along the way. In an effort — however misguided — to give the boy some sense of a normal life, she has convinced him that “Room” is all there is. To him, this cramped garden shed — configured with heat, a bathroom, a TV, and a kind of kitchen — is the world. It’s all he knows and all she’s allowed him to know. But now that he’s five, Ma decides he’s old enough to know the truth, something he is resistant to learning. She also wants him to help her in securing their escape, something he is unprepared for. Both things are certainly understandable in a child of five.

That roughly forms the first half of the movie, leading us to the film’s most successfully sustained sequence (the escape), followed by the duo’s attempts to adjust to the real world, which is the least successful aspect of the film.

None of what I’ve written qualifies as a spoiler since all of this is clearly established in the trailers and the publicity for the film. Abrahamson and the author are more assured when the story is confined to the confines of room, though your involvement in it may depend on your tolerance for the high-pitched screaming of a five-year-old. I confess mine is limited, which is probably a character flaw on my part.

Once the film moves into the world beyond “Room,” it’s not only Jack who is at a loss of what to make of it all, so are the filmmakers. It starts off reasonably well, but quickly becomes unfocused. Characters appear and disappear. Why is Grandma’s (Joan Allen) second husband (Tom McCamus) the most human and functioning character in the movie? Plot points are raised and quickly dropped — or possibly just forgotten about. Some of this — like the fate of Old Nick and Joy’s father’s (William H. Macy) just vanishing over his inability to cope with the history of Jack’s conception and birth — may be excused as some kind of subtlety. So much feels like it exists only to get to an ending that’s perhaps more simplistic, and dubious, than ambiguous.

Worst of all, the real world aspect in Abrahamson’s latest is curiously flat and lacking in style. It mostly looks like a stale TV drama taking place on sets left over from a 1970s sitcom.

Room is not bad exactly. It’s more just indifferent, which may be worse. But bear in mind, my reservations and tepid response to it are very much in the minority.