Prerequisites: finish the game once so New Game Plus unlocks - coins, Strange Books, and the Strange Access Card only exist in NG+. Dog ending = deposit all 3 coins in Guide Dog banks, then beat the boss. Sci-Fi = 3 Strange Books + Access Card on the hallway reader, which skips the boss entirely.

1Dog Ending - "Let's Talk This Out"

2Sci-Fi Ending - "Sci-fi-lent Hill"

3All Endings From One NG+ Run

Collect every coin, book, and the card. Make manual saves at two points: after the first two coins / early books, and again just before the final hallway (after the container drop, before using the card or walking to the boss).
Then reload to pick: use the card → Sci-Fi (skips boss). Skip the card, beat the boss with all three coins deposited → Dog. Skip both sequences → whatever main ending your Discoveries/kills ratio produced.
Main endings still tally the whole run. Community numbers circulating: Justice needs Discoveries roughly 20+ above kills (kills under 60); Forever is a small Discoveries lead with kills under 60; Abandoned is high kills / ignoring most Discoveries. The joke endings override this.

Common Mistakes

Watch the NG+ Endings Walkthrough

All NG+ endings: coin deposits, symbol-door code, and the Access Card swipe: