I wonder what is the last ending ? MC pick up the soap maybe
He did mention on Patreon what he was thinking for the fifth route:
"Fifth route, [Name still not decided]:
I'm not sure how much into detail I want to go on this, or whether I want to keep it as a surprise. But basically, there's like four or five different choices in PL that lead to a game over screen. The idea with this ending is to expand upon that, and get rid of the "game over" screens in the game entirely, and instead, have those be routes in in of themselves. The only exceptions would be the two fights in PL. Losing those would still lead to the game over screen."
However, he did also say that he may not even implement a 5th route. So we may only have 4 ending in the final game.
