Starting up the Resident Evil 4 demo has a random chance to let you play its Mad Chainsaw difficulty mode.​

The recently-released demo for Resident Evil 4 remake, dubbed the Chainsaw Demo, has a secret difficulty mode. According to Eurogamer, players have discovered that completing the demo once gives them the option to attempt it again with a new “extreme difficulty” mode, titled Mad Chainsaw Mode.

The new difficulty mode can be accessed for a single play through after finishing the demo once. If you want to attemt Mad Chainsaw Mode again, you’ll have to wait for the difficulty mode to unlock once again. The demo also states that Mad Chainsaw Mode is exclusive to the Resident Evil 4 remake demo, and will not be present in the full game.

Unlocking Mad Chainsaw Mode seems to have less to do with actually finishing the demo and more to do with random chance. The difficulty mode seemingly triggers at random any time you start the demo.

Mad Chainsaw Mode features stronger enemies, as well as different placement for different enemies. It also lacks checkpoints, and the first chainsaw-based enemy of the game—Dr. Salvador—will be on fire when he appears in the demo.

The Resident Evil 4 remake demo was released earlier this week, and is available on PC, PS4, PS5, Xbox One, and Xbox Series X/S. The game is slated to release on all platforms on March 24.