Games like Athanasia
Games like Athanasia include Half-Life: Alyx, Project Silverfish, Half-Life 2, Prey, and Black Mesa. We matched them by the tags players give Athanasia on Steam (Immersive Sim, Dinosaurs, FPS, Exploration, and Retro): closest matches first, and among equally close ones the better-known games.

Half-Life: Alyx
Shared: FPS · Female Protagonist · Shooter

Project Silverfish
Shared: Immersive Sim · FPS · Exploration

Half-Life 2
Shared: FPS · Action · Shooter

Prey
Shared: Immersive Sim · FPS · Sci-fi

Black Mesa
Shared: FPS · Action · First-Person

Bright Memory
Shared: FPS · Female Protagonist · Shooter

Gloomwood
Shared: Immersive Sim · FPS · Exploration

BioShock Infinite
Shared: FPS · Action · Shooter

System Shock
Shared: Immersive Sim · Action · FPS

Resident Evil Requiem
Shared: FPS · Action · Horror

Bright Memory: Infinite
Shared: FPS · Female Protagonist · Action

PIGFACE
Shared: Immersive Sim · FPS · Shooter

ORION: Prelude
Shared: Dinosaurs · FPS · Action

Metro Exodus
Shared: FPS · Action · First-Person

Selaco
Shared: FPS · Female Protagonist · Shooter

S.T.A.L.K.E.R.: Shadow of Chornobyl - Enhanced Edition
Shared: Exploration · Action · FPS

Fallout 4
Shared: Exploration · Shooter · FPS

Far Cry® 6
Shared: FPS · Action · Shooter

Twisted Tower
Shared: Exploration · FPS · Immersive Sim

METRO Last Light Redux
Shared: FPS · Action · Horror

METRO 2033 Redux
Shared: FPS · Action · Horror

Left 4 Dead 2
Shared: FPS · Shooter · Action

Ready or Not
Shared: FPS · Shooter · First-Person

DEATHLOOP
Shared: FPS · Immersive Sim · Action