Andrew Wyatt’s review published on Letterboxd :
There’s enticing potential in the concept that undergirds Thierry Poirand’s 'Don’t Grow Up', which adds a wrinkle to the now-familiar apocalyptic horror convention of a “rage virus.” In this case, the epidemic only affects adults. The film starts out promisingly, centering its narrative on a colorful group of adolescents who have been left unsupervised over a long holiday break at their state-run home. Initially, Poirand’s decision to render this tale through the eyes of variously orphaned, delinquent, and mentally ill kids — all of them distrustful and prematurely self-reliant — seems like it’s going to pay thematic dividends. The film suggests that the contagion’s onset might be linked to emotional maturity rather than biological age, but then leaves this notion unexplored as it gets bogged down in a tired zombocalypse plot featuring a predictable pattern of lulls, attacks, and escapes. Even the film’s forlorn, faintly impressionistic cinematography can’t compensate for the disappointing sense of triteness that eventually settles over the story.