Games like Fiendish Quest
Games like Fiendish Quest include Vampires' Melody, Storyteller, Spirit of the North, Florence, and 月に寄りそう乙女の作法. We matched them by the tags players give Fiendish Quest on Steam (Casual, Adventure, Interactive Fiction, Walking Simulator, and Visual Novel): closest matches first, and among equally close ones the better-known games.

Vampires' Melody
Shared: Casual · Adventure · Visual Novel

Storyteller
Shared: Interactive Fiction · Adventure · Puzzle

Spirit of the North
Shared: Adventure · Casual · Puzzle

Florence
Shared: Casual · Adventure · Interactive Fiction

月に寄りそう乙女の作法
Shared: Casual · Visual Novel · Adventure

No Case Should Remain Unsolved
Shared: Interactive Fiction · Puzzle · Visual Novel

Refind Self: The Personality Test Game
Shared: Interactive Fiction · Adventure · Visual Novel

OPUS: Echo of Starsong - Full Bloom Edition
Shared: Visual Novel · Interactive Fiction · Adventure

Turnip Boy Commits Tax Evasion
Shared: Puzzle · Exploration · Casual

Marco & The Galaxy Dragon
Shared: Adventure · Visual Novel · Casual

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

Mirror 2: Project X
Shared: Interactive Fiction · Visual Novel · Casual

Until Then
Shared: Visual Novel · Interactive Fiction · Adventure

The Hungry Lamb: Traveling in the Late Ming Dynasty
Shared: Visual Novel · Interactive Fiction · Adventure

Slime Rancher
Shared: Adventure · Exploration · Casual

Scribblenauts Unlimited
Shared: Casual · Adventure · Puzzle

DAVE THE DIVER
Shared: Casual · Adventure · Exploration

Killer Frequency
Shared: Adventure · Interactive Fiction · Puzzle

Koi x Shin Ai Kanojo
Shared: Casual · Adventure · Visual Novel

Pikuniku
Shared: Adventure · Casual · Puzzle

[Chilla's Art] The Radio Station | 深夜放送
Shared: Casual · Adventure · Interactive Fiction

TOEM: A Photo Adventure
Shared: Adventure · Puzzle · Casual

Lay a Beauty to Rest: The Darkness Peach Blossom Spring
Shared: Adventure · Visual Novel · Interactive Fiction

Aonatsu Line
Shared: Casual · Adventure · Interactive Fiction