GTA IV is, from one perspective, in danger of taking itself too seriously. But the corollary is the outrageously exciting prospect of anyone taking the construction of a videogame world this seriously at all, let alone a developer as gifted and influential as Rockstar North. Even just breathing in the scant PR fumes Rockstar is allowing to escape at present – a hint here, a suggestion there – is intoxicating. The subtle, humane ambition of the plot only adds to the bold, superhuman ambition of creating a virtual city this lifelike, with this much scope for complexity. Even if the unthinkable happens and the game itself falls short, the signs are that the new Liberty City will be an unforgettable creation, and a worthy tribute to the spectacle, diversity and dynamism of its inspiration.