Mature Content Description

The developers describe the content like this:

Adds an option to change the protagonist's cup size to P cup.

About This Content

This optional DLC adds a new game mode and cosmetic options for Karryn's Prison!

Some have called it a world wonder actually. The marvels of human engineering. The peak of culture. But let's talk about what's actually inside this DLC. The first addition is the titular tits that Karryn can now possess. This is a completely optional cosmetic that took a painstaking and loving year to mound into flesh.

The second addition is the all new Descension Runs. After beating the game once, there is now a new option available before starting a new run. Deep in the depths of Karryn's Prison is a new difficulty mode called Descension.

A Descension run composes of a series of scenarios.
A scenario composes of 'Unique' and 'Carryover' effects that warps normal gameplay.
'Unique effects' are only active during that scenario.
'Carryover effects' are active for the rest of the Descension run.

A scenario is won upon beating the final boss.
After beating the scenario, you will return back to the scenario selection.
You will then have a choice between continuing the Descension run by picking a new scenario, or quitting the current Descension run.
You will also be able to quit the Descension run after getting a Game Over.

Descension runs can be played on any difficulty.
Doing a Descension run will reset all levels and stats, and cancel any selected Challenge run.
The five different scenarios can be picked in any order.

There's two different type of obtainable Titles as a reward for doing Descension runs:

The first type of Titles is rewarded for beating a scenario for the first time on Warden Mode or higher.
It will allow you to enable the Carryover effect of that scenario during any normal run.

The second type of Titles is rewarded for beating multiple scenarios on Prisoner Mode.
Which means beating a scenario, and then continuing the Descension run to keep descending.

How far will Karryn descend in order to complete a full Descension run?