'Open-world survival game with zombies' DayZ has broken the 1m sales mark in four weeks.
"So much for the death of PC gaming," wrote Dean Hall on Twitter, announcing the news.
Such a figure is "way beyond - way, way beyond" what he had expected, he admitted. "This gives me mandate now to make all the crazy games I ever wanted!"
DayZ is currently in alpha form, and available from Steam as an Early Access title for £20. At the time of publication it's the top selling game on Valve's digital platform.