Well I played as much as I could. Couldn't find the 4th ending aside from 1,2, and 3 (so maybe last is true end?)
SPOILER DON'T READ IF YOU DON'T WANT LORE SPOILED
But from my take on this game, Veronikka just wanted a quiet life while doing her to-do list, but Milena (that's most likely but maybe not) maybe tampered with it making Veronikka injure herself because of an OCD to complete the to-do list. (hence why she said in the S note that it's "gross but still in the to-do list" and had to do so) Meanwhile there's other things going on around her with "that man" and something's off about Esther (I mean obviously after you find the basement but the sailor scouts had more to say) so hopefully at some point i can find a 4th ending. Aside from the ost playing a lot which makes playing a bit tedious (maybe change every now and then depending on the building?) but good job on the game :)