Debug mode is resource-heavy. Running the debug menus, spawning massive hordes, and rapid-fire teleporting can cause memory leaks and crashes more frequently than the stable standard build. You are, after all, running a developer build of the game.
Try it once just to see how the game ticks, but don't let it replace the thrill of a genuine, vulnerable survival run. project zomboid debug scenarios
Advanced users can write custom .lua scenario files in: ProjectZomboid/media/lua/client/DebugScenarios/ Debug mode is resource-heavy
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Using the tools to curate a challenge, rather than solve it, is where this mode shines. spawning massive hordes