Earlier levels in the game have been made accessible.
The Electric Wasteland has major changes that may be easier and more fun in general to maneuver around, as well as extra lore. The boss is easier to speedrun as well, by walking off bounds to speed up the autoscroll.
Various other levels like Level 2 and Level 3 have small tweaks that may add great convenience.
The Specular Chamber now has a visual overhaul in some areas.