The key to making retro games work – as Space Invaders Extreme 2 and its predecessor realise – is to revel in nostalgia, while at the same time bringing the gameplay up to more modern standards. As with the first title, Extreme 2 is a chunky pixel soup made from equal parts Space Invaders and Rez; it’s half shoot-’em-up and half rhythm game, making the (obvious, when you think about it) connection between the two.