The open world zombie survival game Dying Light official turns 4-years-old today. To celebrate the occasion, developer Techland is hosting an in-game event that rewards players with double XP while unique legacy items including the Rocket League Buggy Skin will be given away.

Released in 2015, Dying Light has attracted over 16 million players worldwide. According to Techland, not only have game sales resisted decline, they actually increased in the past year. The developer achieved this feat by continuously supporting the game with content such as The Following expansion pack, in-game drops, the “10-IN-12” free DLC program, and regular in-game events.

“The last four years have brought not only Dying Light, but also the whole company to a whole new level – our development and publishing teams have grown in people whose passion directly shows in our games,” said Techland CEO, PaweĊ‚ Marchewka in a statement.

With a little luck, Dying Light could get in another four years of zombie bashing action. The game is available now for PC, Xbox One, and PlayStation 4.