David Oyelowo’s performance in Selma single-handedly confirmed his status as a consummate actor. The Water Man, hopefully, won’t define Oyelowo’s less practised and less effective skills behind the camera.

A children’s story with a screenplay by Emma Needell, Oyelowo imbues The Water Man with as much wonder and sincerity as he can, but it doesn’t make up for some mediocre acting and disappointingly amateur aesthetics. As the paternal lead Amos, alongside Rosario Dawson as mother Mary and Lonnie Chavis (the couple’s son Gunner), Oyelowo has more success as a performer than a director. That might be inevitable considering his prolific work as an actor and inexperience behind the camera, but it doesn’t justify some of the less sensible visual choices Oyelowo and cinematographer Matthew J Lloyd opt to make.

Charting Gunner’s creative journey while he comes to terms with his mother’s terminal illness, The Water Man begins with a move to a new city and Gunner’s adaptation to his father’s return to the home. Oyelowo directs the affluent but fraught family home with a little too much style, presumably in an effort to avoid the sort of poverty-stricken representation of black family life that films too often fixate on. That decision makes social sense but it doesn’t do much to illustrate the high stakes The Water Man is playing with. Mary’s sickness, although carefully and sensitively portrayed by Dawson, doesn’t quite get its due, either.

The story quite quickly develops into a Bridge to Terabithia-style adventure in which Gunner seeks a cure for his mother’s disease alongside an unlikely companion. Alfred Molina briefly appears as a kooky intellectual and a potential ally, but it’s little more than a bit part for the great actor.

Ultimately, The Water Man isn’t grounded enough in its intriguing human relationships, opting for a half-baked adventure that never ties the two together. Too rushed to be epic and too messy to be especially meaningful, Oyelowo’s debut scuppers some early promise for a limp final act that piles on the schmaltz without ever having earned it. From a great artist on the other side of the camera, we should expect better next time.