Games like Once Upon
Games like Once Upon include Undertale, The Witcher 3: Wild Hunt — Remastered, The Life and Suffering of Sir Brante, Suzerain, and Aliya: Timelink. We matched them by the tags players give Once Upon on Steam (RPG, Interactive Fiction, Text-Based, Artificial Intelligence, and Choices Matter): closest matches first, and among equally close ones the better-known games.

Undertale
Shared: Choices Matter · RPG · Story Rich

The Witcher 3: Wild Hunt — Remastered
Shared: RPG · Story Rich · Choices Matter

The Life and Suffering of Sir Brante
Shared: RPG · Interactive Fiction · Choices Matter

Suzerain
Shared: Interactive Fiction · Choices Matter · Text-Based

Aliya: Timelink
Shared: RPG · Interactive Fiction · Multiple Endings

Roadwarden
Shared: RPG · Text-Based · Interactive Fiction

Baldur's Gate 3
Shared: RPG · Choices Matter · Story Rich

The Witcher 2: Assassins of Kings Enhanced Edition
Shared: RPG · Choices Matter · Story Rich

Dragon Age: Origins - Ultimate Edition
Shared: RPG · Choices Matter · Story Rich

Detroit: Become Human
Shared: Choices Matter · Multiple Endings · Story Rich

Road to Empress I
Shared: RPG · Choices Matter · Story Rich

Esoteric Ebb
Shared: RPG · Choices Matter · Story Rich

Mass Effect™ Legendary Edition
Shared: RPG · Choices Matter · Story Rich

STAR WARS™ Knights of the Old Republic™ II - The Sith Lords™
Shared: RPG · Story Rich · Choices Matter

Disco Elysium - The Final Cut
Shared: RPG · Choices Matter · Story Rich

Volcano Princess
Shared: RPG · Choices Matter · Multiple Endings

The Witcher: Enhanced Edition Director's Cut
Shared: RPG · Choices Matter · Story Rich

Road to Empress Ⅱ
Shared: Choices Matter · Interactive Fiction · RPG

Legend of Mortal
Shared: RPG · Choices Matter · Multiple Endings

Back to the Dawn
Shared: RPG · Choices Matter · Story Rich

Choice of Robots
Shared: Text-Based · Interactive Fiction · Choices Matter

Mirror 2: Project X
Shared: Interactive Fiction · RPG · Multiple Endings

Love Is All Around
Shared: Interactive Fiction · Singleplayer · Multiple Endings

风信楼
Shared: Interactive Fiction · Choices Matter · Multiple Endings