Games like Lightout
Games like Lightout include Poppy Playtime, Little Nightmares II, Outlast, Little Nightmares, and SOMA. We matched them by the tags players give Lightout on Steam (Horror, Puzzle, Atmospheric, Adventure, and Thriller): closest matches first, and among equally close ones the better-known games.

Poppy Playtime
Shared: Horror · Puzzle · Dark

Little Nightmares II
Shared: Horror · Puzzle · Adventure

Outlast
Shared: Horror · Atmospheric · Psychological Horror

Little Nightmares
Shared: Horror · Atmospheric · Adventure

SOMA
Shared: Horror · Atmospheric · Psychological Horror

Amnesia: The Dark Descent
Shared: Horror · Atmospheric · Puzzle

Inside the Backrooms
Shared: Horror · Puzzle · Psychological Horror

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

Detention
Shared: Horror · Atmospheric · Puzzle

Outer Wilds
Shared: Adventure · Exploration · Atmospheric

Darkwood
Shared: Horror · Adventure · Psychological Horror

The Room Two
Shared: Puzzle · Atmospheric · Horror

Backrooms: Escape Together
Shared: Horror · Psychological Horror · Atmospheric

Firework
Shared: Horror · Puzzle · Atmospheric

Garten of Banban
Shared: Horror · Puzzle · Psychological Horror

Mouthwashing
Shared: Horror · Atmospheric · Psychological Horror

Fran Bow
Shared: Puzzle · Horror · Psychological Horror

ROUTINE
Shared: Atmospheric · Psychological Horror · Horror

Layers of Fear (2016)
Shared: Horror · Atmospheric · Psychological Horror

Bendy and the Ink Machine
Shared: Horror · Puzzle · Dark

Resident Evil 7 Biohazard
Shared: Horror · Atmospheric · Psychological Horror

Outlast 2
Shared: Horror · Psychological Horror · Atmospheric

DARQ: Complete Edition
Shared: Horror · Puzzle · Adventure

MADiSON
Shared: Horror · Puzzle · Psychological Horror