On paper, it was a creaky set-up – low on tension, riddled with contortions of logic and culminating in the kind of cliched gunfight TV cop shows have routinely dispensed with for the past 25 years. But the action zipped by so breezily the thinness of the premise scarcely mattered: the trip was such a hoot who cared where it was leading? Though dark and brooding in its visual style, Gotham is, at its core, cheerfully frothy – a series that seeks to be loved rather than admired, to entertain rather than engage the intellect. Far from a drawback, cheesy exuberance has turned out to be its most charming quality.