Games like Helen's Mysterious Castle
Games like Helen's Mysterious Castle include Undertale, Tales of the Black Forest, OneShot, CrossCode, and To the Moon. We matched them by the tags players give Helen's Mysterious Castle on Steam (RPG, Indie, Female Protagonist, Casual, and Anime): closest matches first, and among equally close ones the better-known games.

Undertale
Shared: RPG · Pixel Graphics · Indie

Tales of the Black Forest
Shared: RPG · Indie · Pixel Graphics

OneShot
Shared: Indie · Pixel Graphics · Cute

CrossCode
Shared: RPG · Female Protagonist · Pixel Graphics

To the Moon
Shared: Indie · Pixel Graphics · RPG

Touhou Mystia's Izakaya
Shared: RPG · Casual · Pixel Graphics

Muse Dash
Shared: Anime · Female Protagonist · Casual

DELTARUNE
Shared: RPG · Pixel Graphics · Singleplayer

Greyfox RPG
Shared: Indie · RPG · Anime

Celeste
Shared: Indie · Pixel Graphics · Female Protagonist

Tales of Berseria™
Shared: RPG · Anime · Female Protagonist

NieR:Automata™
Shared: RPG · Female Protagonist · Great Soundtrack

OMORI
Shared: Indie · RPG · Pixel Graphics

Chained Echoes
Shared: RPG · Indie · Pixel Graphics

CHRONO TRIGGER®
Shared: RPG · JRPG · Pixel Graphics

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

A Bird Story
Shared: Indie · Pixel Graphics · RPG

Montaro
Shared: Indie · Casual · Anime

Volcano Princess
Shared: RPG · Female Protagonist · Anime

Eastward
Shared: RPG · Pixel Graphics · Singleplayer

FINAL FANTASY® XIII
Shared: RPG · Female Protagonist · JRPG

Recettear: An Item Shop's Tale
Shared: RPG · Anime · Indie

The Witch's House MV
Shared: Indie · RPG · Pixel Graphics

Vampire Survivors
Shared: Indie · Pixel Graphics · Casual