Games like CINERIS IV
Games like CINERIS IV include Outer Wilds, Firewatch, No Man's Sky, Starfield, and Deliver Us The Moon. We matched them by the tags players give CINERIS IV on Steam (Mystery, Thriller, Space, Singleplayer, and Sci-fi): closest matches first, and among equally close ones the better-known games.

Outer Wilds
Shared: Mystery · Space · Adventure

Firewatch
Shared: Mystery · Adventure · Singleplayer

No Man's Sky
Shared: Space · Sci-fi · Exploration

Starfield
Shared: Space · Singleplayer · Sci-fi

Deliver Us The Moon
Shared: Space · Adventure · Sci-fi

The Invincible
Shared: Adventure · Sci-fi · Space

What Remains of Edith Finch
Shared: Mystery · First-Person · Singleplayer

Poppy Playtime
Shared: Singleplayer · Mystery · First-Person

Observation
Shared: Space · Adventure · Sci-fi

Subliminal
Shared: Mystery · Singleplayer · Thriller

ROUTINE
Shared: Singleplayer · Sci-fi · Psychological Horror

Prey
Shared: Space · Sci-fi · Singleplayer

STAR WARS Jedi: Survivor™
Shared: Singleplayer · Adventure · Sci-fi

Elite Dangerous
Shared: Space · Sci-fi · Exploration

Fallout 4
Shared: Singleplayer · Adventure · Exploration

No, I'm not a Human
Shared: Singleplayer · Psychological Horror · Indie

Five Nights at Freddy's: Security Breach
Shared: Singleplayer · First-Person · Adventure

Moons of Madness
Shared: Adventure · Space · Sci-fi

Breathedge
Shared: Space · Singleplayer · Sci-fi

The Talos Principle
Shared: Sci-fi · First-Person · Singleplayer

Half-Life 2
Shared: Sci-fi · Singleplayer · Action

Valley
Shared: Adventure · Singleplayer · First-Person

Tacoma
Shared: Sci-fi · Space · Adventure

Marvel's Guardians of the Galaxy
Shared: Singleplayer · Sci-fi · Space