Joe Cornish (of 'Adam & Joe' near-fame) pulls a blinder in his directorial debut: a fine monster movie, imbued with wry humour and disarming pathos. The efficient plot involves a teen gang in South London defending their block from an alien invasion, after encountering (and brutalising) one of the invaders. The eponymous block becomes a strong character in its own right, resplendent in drizzle, sodium yellow streetlights and piss-stained lifts, and this familiarity provides the source for much of the enjoyment, providing a stark and refreshing twist to the genre. Of course, the same was said of the excellent Shaun of the Dead (to which inevitable comparisons abound) but this owes much more of a debt to the homegrown eeriness of John Wyndham and H G Wells (rather than Edgar Wright's increasingly Yankophilic efforts, all indebted to Hollywood tropes) and is all the better for it. Cornish even has the nerve to add a dash of credible social realism to it. Highly recommended.