Mod menus typically offer a suite of "trainer" style options that significantly alter gameplay:

Because this is the Definitive Edition, some menus tap directly into the Unreal Engine console. This allows you to remove fog, adjust the "Lumen" lighting (dynamic global illumination), and change the "Post Process" material, returning the game to the classic vibrant pink/teal palette many felt was lost.

Mod menus are also available for the mobile and Netflix versions of the Definitive Edition. These typically require installing a modified APK file and granting specific permissions to allow the menu to overlay on the game screen.