Games like The Creepy Syndrome
Games like The Creepy Syndrome include The Test, No, I'm not a Human, Undertale, OneShot, and Detroit: Become Human. We matched them by the tags players give The Creepy Syndrome on Steam (Choices Matter, Story Rich, Retro, Multiple Endings, and Puzzle): closest matches first, and among equally close ones the better-known games.

The Test
Shared: Story Rich · Multiple Endings · Choices Matter

No, I'm not a Human
Shared: Choices Matter · Story Rich · Horror

Undertale
Shared: Story Rich · Choices Matter · Multiple Endings

OneShot
Shared: Story Rich · Choices Matter · Puzzle

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

Ib
Shared: Story Rich · Horror · Pixel Graphics

The Casting of Frank Stone™
Shared: Choices Matter · Multiple Endings · Story Rich

OMORI
Shared: Story Rich · Psychological Horror · Multiple Endings

The Coffin of Andy and Leyley
Shared: Story Rich · Multiple Endings · Choices Matter

The Wolf Among Us
Shared: Story Rich · Choices Matter · Multiple Endings

Outer Wilds
Shared: Story Rich · Exploration · Puzzle

KinitoPET
Shared: Retro · Horror · Story Rich

Slay the Princess — The Pristine Cut
Shared: Choices Matter · Story Rich · Horror

Zero Escape: The Nonary Games
Shared: Story Rich · Choices Matter · Puzzle

Outcore: Desktop Adventure
Shared: Story Rich · Psychological Horror · Choices Matter

The Test: Hypothesis Rising
Shared: Choices Matter · Multiple Endings · Story Rich

Sally Face - Episode One
Shared: Story Rich · Puzzle · Horror

Death and Taxes
Shared: Choices Matter · Story Rich · Multiple Endings

Papers, Please
Shared: Multiple Endings · Story Rich · Puzzle

Milk outside a bag of milk outside a bag of milk
Shared: Story Rich · Psychological Horror · Multiple Endings

Zero Escape: Zero Time Dilemma
Shared: Story Rich · Puzzle · Choices Matter

Until Dawn™
Shared: Choices Matter · Multiple Endings · Horror

Mouthwashing
Shared: Story Rich · Retro · Horror

Endacopia
Shared: Puzzle · Horror · Psychological Horror