Having conquered the Chinese box office with the superhit Monkey King: Hero Is Back in 2015, director Tian Xiaopeng plunges into the whirlpool of childhood blues for his latest animated adventure. In contrast to the earlier film, which was drawn from the 16th-century novel Journey to the West, Deep Sea carries Tian’s first original screenwriting credit. While fantastical elements abound, the story is at its heart a coming-of-age tale about weathering the storm of grief and trauma.

The central figure is a young girl called Shenxiu. Abandoned by her mother after her parents’ divorce, she also feels alienated from her father and his new wife, whose attention is showered solely on their own child. Outside, the world seems as hopelessly grey as Shenxiu’s nightmares, in which she constantly trails after her elusive mother. Even on a cruise with her family, she is lonesome and unmoored.

When a fearsome thunderstorm strikes the cruise ship, however, the icy animation spectacularly changes, and Shenxiu finds herself transported to a kaleidoscopic underwater restaurant called Deep Sea frequented by anthropomorphic fish, walruses and fantastical creatures. Run by rakish chef Nanhe, the eatery’s chaotic operations seem to be an excuse for the film to flex its CGI prowess – sometimes at the cost of narrative coherence.

Rarely staying still, characters and objects constantly bounce and hurl themselves around. The result can be dazzling, yet the visual overload is repetitive and exhausting. Much of the film’s emotional crux also rests on a redemption arc that feels slight amid the bombastic onslaught of visual tricks. Despite the tonal unevenness, however, the mix of hyperreal 3D animation and impressionistic compositions using the techniques of Chinese painting is unique to behold, like a tableaux roused into breathtaking life.

• Deep Sea is in UK cinemas from 7 June.