Games like Valiantia
Games like Valiantia include Undertale, South Park™: The Stick of Truth™, CrossCode, Reventure, and Ten Trials of Babel: The Doppelganger Maze. We matched them by the tags players give Valiantia on Steam (Multiple Endings, Comedy, Female Protagonist, RPG, and 2D): closest matches first, and among equally close ones the better-known games.

Undertale
Shared: Multiple Endings · RPG · Comedy

South Park™: The Stick of Truth™
Shared: Comedy · RPG · Adventure

CrossCode
Shared: Female Protagonist · RPG · Puzzle

Reventure
Shared: Multiple Endings · Comedy · Adventure

Ten Trials of Babel: The Doppelganger Maze
Shared: Multiple Endings · Female Protagonist · RPG

Tales of the Black Forest
Shared: RPG · Female Protagonist · Adventure

Evoland
Shared: RPG · Adventure · Retro

Finding Paradise
Shared: 2D · RPG · Adventure

There Is No Game: Wrong Dimension
Shared: Puzzle · Comedy · Adventure

South Park™: The Fractured But Whole™
Shared: Comedy · RPG · Adventure

Kindergarten 2
Shared: Adventure · Puzzle · Comedy

Papers, Please
Shared: Multiple Endings · Puzzle · Indie

OneShot
Shared: Puzzle · Multiple Endings · 2D

Shadows Over Loathing
Shared: RPG · Comedy · Adventure

Cthulhu Saves the World
Shared: Comedy · RPG · JRPG

OMORI
Shared: Multiple Endings · RPG · 2D

The Henry Stickmin Collection
Shared: Multiple Endings · Comedy · 2D

West of Loathing
Shared: Comedy · RPG · Adventure

Deponia
Shared: Comedy · Puzzle · Adventure

Volcano Princess
Shared: Multiple Endings · Female Protagonist · RPG

Touhou Mystia's Izakaya
Shared: RPG · Comedy · 2D

月华辉映之刻
Shared: Female Protagonist · Multiple Endings · RPG

Hyperdimension Neptunia Re;Birth1
Shared: Female Protagonist · RPG · Comedy

Greyfox RPG
Shared: RPG · Adventure · Female Protagonist