Games like FLARE
Games like FLARE include Half-Life 2, Portal 2, Black Mesa, Portal, and Cyberpunk 2077. We matched them by the tags players give FLARE on Steam (Action, Atmospheric, Singleplayer, Combat, and Sci-fi): closest matches first, and among equally close ones the better-known games.

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

Portal 2
Shared: Singleplayer · Puzzle · Platformer

Black Mesa
Shared: Action · Sci-fi · Singleplayer

Portal
Shared: Singleplayer · Sci-fi · 3D Platformer

Cyberpunk 2077
Shared: Singleplayer · Sci-fi · Atmospheric

BioShock Infinite
Shared: Action · Singleplayer · Atmospheric

Titanfall® 2
Shared: Singleplayer · Action · FPS

Black Myth: Wukong
Shared: Action · Combat · Singleplayer

Crysis Remastered
Shared: Action · Sci-fi · Singleplayer

Prey
Shared: Sci-fi · Singleplayer · Atmospheric

Ready or Not
Shared: Singleplayer · Realistic · FPS

Atomic Heart
Shared: Action · Singleplayer · FPS

Call of Duty®: Black Ops III
Shared: Action · Singleplayer · FPS

RoboCop: Rogue City
Shared: Action · Singleplayer · FPS

Metal Garden
Shared: Atmospheric · Singleplayer · Sci-fi

Deus Ex: Mankind Divided
Shared: Action · Sci-fi · Atmospheric

Half-Life: Opposing Force
Shared: Action · Singleplayer · Sci-fi

Battlefield™ 2042
Shared: Singleplayer · Action · FPS

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

BioShock™
Shared: Atmospheric · Action · Singleplayer

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

Half-Life: Blue Shift
Shared: Action · Singleplayer · Sci-fi

Ori and the Will of the Wisps
Shared: Action · Singleplayer · Atmospheric

Fallout 4
Shared: Singleplayer · Atmospheric · Action