From the beginning I considered that the level progression would be with the store arrangement changing each level (in real life stores will sometimes completely rearrange the isles and you need to rediscover your way around, which is annoying), and the number of NPCs increasing, but progressively getting more perks at your disposal.
Within level progression however would be different as the store changes in appearance according to anxiety levels, it gets brighter and bleaker, some pathways will be blocked forcing the player to find other pathways to get to the items and the quiet areas.
Examples of items becoming hard to read and distinguish according to anxiety levels. This should lead to the player picking the wrong items, such as a can of baked beans instead of a can of tomato paste.
They should also change appearance while in the inventory.
