Steam’s free weekend deals used to stretch a good way into Monday for us Brits. Now they seem to stop at 1pm on Sunday for the West coast Americans, which seems very peculiar – surely Sunday afternoon would be the prime free playing time? Still, in the Mother Country that means it stretches until 9pm. And this weekend there’s quite the choice. The absolutely superb XCOM: Enemy Unknown, at 75% off (that’s just £7.50 – cripes), and free to play for the next three days. And there’s Retrovirus, the great six-axis shooter that I bet you never played. Now you can pick it up with 60% off at £6, and also play it for free until Sunday.