Zombie games can still bring in big sales, as publisher Focus Home Interactive and developer Saber Interactive announced today that their co-op shooter World War Z has passed more than 1 million copies sold since its April 16 launch on PC, PlayStation 4, and Xbox One. It accomplished this despite not being on Steam — it’s an Epic Games Store exclusive for PC. This is a fantastic showing for Saber, the New Jersey-based studio that put out Shaq-Fu: A Legend Reborn and NBA 2K Playgrounds 2 last year.

Saber Interactive CEO Matthew Karch said that World War Z is better than he’d thought it would outside the U.S. and that at its peak, World War Z had 70,000 concurrent players during launch week. Our Dean Takahashi thinks it could appeal to fans who enjoy games like Left 4 Dead and other co-op shooting experiences.

“Overall the U.S. and EU have been equally strong in sales. We have had 70,000 people playing at once across all platforms, with very similar distribution among PC (Epic Games Store), PS4 and Xbox. What surprises us is the fact that sales outside of the U.S. on the Epic Store have been so strong, with the U.S. being only one quarter of sales.”

World War Z is a third-person co-op shooter. In the campaign mode, up to four people can work together to take on the hordes of zombies. Multiplayer has what Saber calls “PvPvZ” which is players-vs.players-vs.-zombies. Your squad takes on another group of players while both hold off rampaging zombies. And remember: These are the fast-moving zombies of the film, which can move about in great herds, and not the slower walking dead of the original novel.

Earlier this month, Focus Home and Saber Interactive strengthened their relationship. The excellent performance of World War Z shows Focus Home’s faith in Saber was justified.