Steam owners of Dying Light can now download the game's Developer Tools pack and begin creating their own custom content.
Head to your Steam library and you'll be able to nab the new level editor now.
A trailer, shown below, details some of the possibilities open to players - such as undead-strewn mazes, challenges and your own mini-games.
Dying Light developer Techland has also released a series of in-depth video guides that detail the level editor's inner workings in full.
"We plan to release more in-depth videos in the coming weeks to showcase more advanced capabilities of our tools," Techland wrote via the Dying Light Steam page.
"As always, we're restlessly waiting for your feedback. Our Developer Tools will be regularly expanded with new possibilities and updates, so what you say and what you create do matter to us. If there's anything particular that you want to see corrected, speak up!"
Mod support for Dying Light was temporarily removed - in error, Techland later said - by an initial patch for the game, but was restored shortly after.
Here's the sort of thing you can now get up to: