Doug and Kayleen are long-time friends. We meet them first at eight, then at 38 and somewhere inbetween. With little theoretically in common at the start of their relationship, a relentless swathe of injuries and illness and an unspoken feeling of being a permanent outsider brings them together over the years. They develop in some ways, but almost regress in others, never quite achieving true adulthood, scarred in every which way, visibly and mentally.

Their friendship is fractious and furious but sweet and subdued too. The two never quite see eye-to-eye, though, and moments of connection are few and far between. You get the feeling that had these two ever really found each other, perhaps Doug’s life would have taken a completely different path – one that didn’t include telegraph poles and school roofs, gashes and gouges and even eventual paralysis.

The super-talented Felix Scott, so impressive in The Chair Plays at the Lyric Hammersmith recently, is suitably goofy and gawky as Doug, whose understanding of social norms is somewhat flawed, but whose intentions are always good, even when he’s fuming or putting himself in harm’s way. Scott is clearly hugely emotionally invested in the role – Doug’s devastation is visibly etched on his face, and the actor reportedly broke two fingers on press night from an overenthusiastic table-punch.

Mariah Gale’s Kayleen, meanwhile, is ethereal, damaged and isolated, but still strong. This kind of role suits her down to the ground. There’s strong chemistry between Scott and Gale, whose quiet, friendly interaction while daubing each other with gore is pleasant to watch.

Perhaps a touch overlong at 80 minutes, Rajiv Joseph’s story is nonetheless wholly relatable – who hasn’t done something stupid, or left something unsaid for too long? The injuries incurred are violent yet understandable in the main, and while Doug deals in physical scars, Kayleen’s mental traumas are ones many audience members will undoubtedly be able to empathise with.

Supported well by Lily Arnold’s white, clinical set, which traverses the Gate and divides the audience, and by Isobel Waller-Bridge’s well-judged sound design, Gruesome Playground Injuries is not a work of literary genius, but its performances make it a worthwhile watch.

- Miriam Zendle