Games like Paranormal Eclipse
Games like Paranormal Eclipse include Firework, Alan Wake, Half-Life 2, Black Mesa, and Five Nights at Freddy's: Security Breach. We matched them by the tags players give Paranormal Eclipse on Steam (Horror, Thriller, Action, Sci-fi, and Mystery): closest matches first, and among equally close ones the better-known games.

Firework
Shared: Horror · Mystery · Indie

Alan Wake
Shared: Horror · Action · Thriller

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

Black Mesa
Shared: Action · Sci-fi · FPS

Five Nights at Freddy's: Security Breach
Shared: Horror · Singleplayer · Multiple Endings

Atomic Heart
Shared: Action · Horror · Singleplayer

Poppy Playtime
Shared: Horror · Singleplayer · Mystery

Phasmophobia
Shared: Horror · Supernatural · Thriller

Half-Life: Alyx
Shared: Horror · Action · FPS

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

DOOM 3
Shared: Horror · Action · Sci-fi

Aliens vs. Predator™
Shared: Action · Horror · Sci-fi

F.E.A.R.
Shared: Horror · Action · FPS

Ghostwire: Tokyo
Shared: Horror · Supernatural · Singleplayer

DOOM
Shared: Action · FPS · Horror

BioShock™
Shared: Action · Horror · FPS

DOOM 3
Shared: Horror · Action · Sci-fi

Pacify
Shared: Horror · Supernatural · Sci-fi

Dead Space (2008)
Shared: Horror · Action · Sci-fi

Prey
Shared: Sci-fi · Horror · Singleplayer

Bright Memory: Infinite
Shared: Action · Sci-fi · Singleplayer

Singularity™
Shared: Action · Sci-fi · Horror

BioShock™ 2 Remastered
Shared: Action · Horror · Singleplayer

Murdered: Soul Suspect
Shared: Horror · Mystery · Supernatural