I completed the new "Downfall" this evening and got the A ending, called "On the Run".
I had a score of 26 (out of 27).
This ending puzzled me because it did tie in with "The Cat Lady" but I don't understand what actually happend.
In this ending Susan Ashworth killed Joe, but than he came back as the axe murderer.
And it seemed, that the game took place in the apartment house from "The Cat Lady" and the (killed) Joe took the body of his wife while the apartment house burned down or something. This indicates a kind of time loop because he said, he wanted to take his wife to a hotel (in which "Downfall" starts).
It leaves us with - in my opinion - too much questions.
Did Susan Ashworth survive?
Did Joe survive? Is/was he simply mad?
Was it all a misleading game of the queen of maggots?
If so, why?
What is the fat girl in "The Cat Lady" all about?
I want to know, what happens in the other endings.
Did you happen to see one of those? I happen to read, there are at least two endings beside the A ending.

Joe is just wounded... significantly unless you managed a score of zero.

Susan still has her infinite lives.

Joe and Ivy are a total mess regardless of timeline. They are kind of sweet in their own way on the gold timeline at least. Still a mess but sweet.

The fat girl is from the original version... I think.

Isn't the "fat girl" just the way Ivy sees herself?

I think, you're at least partially right.
It seems strange to me, that this form of Ivy is exclusivly seen in "The Cat Lady".
As if the "normal" Ivy doesn't exist.

The world of the Cat Lady/Downfall is a strange one. It wouldn't be weird for the game to only show a mental representation of Ivy instead of a physical one.

I completed Downfall for the second time and got a score of three.
I'm not sure what I can "fuck up" more, to achieve a score of zero.
Of course, I got the A ending again.

For whatever reason the endings are lettered in the order the creator expected us to get the endings.
1-26=A
27=B
0=C

You need to be mean and/or uncaring to everyone trying to help (and Ivy), bro with the party guy, fall for temptation, don't convince Ivy to follow Agnes, blow out a candle, and there are a few things I'm not sure of.

Aiming for that 0 there was this conversation in a flashback that had me frustrated for a bit. You need to pass up one of the bad options because it prematurely ends the conversation the first time it shows up so you can make another bad option.