Games like The Paracelsian Project
Games like The Paracelsian Project include Zero Escape: The Nonary Games, Zero Escape: Zero Time Dilemma, STEINS;GATE, Danganronpa 2: Goodbye Despair, and AI: The Somnium Files. We matched them by the tags players give The Paracelsian Project on Steam (Visual Novel, Puzzle, Multiple Endings, Story Rich, and Mystery): closest matches first, and among equally close ones the better-known games.

Zero Escape: The Nonary Games
Shared: Visual Novel · Puzzle · Story Rich

Zero Escape: Zero Time Dilemma
Shared: Visual Novel · Puzzle · Story Rich

STEINS;GATE
Shared: Visual Novel · Story Rich · Multiple Endings

Danganronpa 2: Goodbye Despair
Shared: Visual Novel · Story Rich · Mystery

AI: The Somnium Files
Shared: Visual Novel · Story Rich · Mystery

The Wolf Among Us
Shared: Story Rich · Multiple Endings · Visual Novel

Danganronpa V3: Killing Harmony
Shared: Visual Novel · Story Rich · Mystery

Danganronpa: Trigger Happy Havoc
Shared: Visual Novel · Story Rich · Mystery

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

The Test
Shared: Multiple Endings · Story Rich · Visual Novel

Raging Loop
Shared: Visual Novel · Mystery · Story Rich

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

The Hungry Lamb: Traveling in the Late Ming Dynasty
Shared: Visual Novel · Multiple Endings · Story Rich

The Test: Hypothesis Rising
Shared: Multiple Endings · Visual Novel · Choices Matter

STEINS;GATE 0
Shared: Visual Novel · Story Rich · Multiple Endings

Phoenix Wright: Ace Attorney Trilogy
Shared: Visual Novel · Story Rich · Mystery

Magical Girl Witch Trials
Shared: Visual Novel · Mystery · Story Rich

The Coffin of Andy and Leyley
Shared: Visual Novel · Multiple Endings · Story Rich

Return to Shironagasu Island
Shared: Visual Novel · Mystery · Story Rich

Tiny Bunny
Shared: Visual Novel · Story Rich · Dark

Return of the Obra Dinn
Shared: Puzzle · Mystery · Story Rich

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

The House in Fata Morgana
Shared: Visual Novel · Story Rich · Mystery

Strange Horticulture
Shared: Puzzle · Mystery · Dark