Games like SICKO SANCTUM 2
Games like SICKO SANCTUM 2 include Half-Life 2, ULTRAKILL, Black Mesa, BioShock Infinite, and DOOM Eternal. We matched them by the tags players give SICKO SANCTUM 2 on Steam (Boomer Shooter, Spectacle fighter, Action, Score Attack, and FPS): closest matches first, and among equally close ones the better-known games.

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

ULTRAKILL
Shared: Boomer Shooter · FPS · Spectacle fighter

Black Mesa
Shared: Action · FPS · First-Person

BioShock Infinite
Shared: Action · FPS · Shooter

DOOM Eternal
Shared: Action · FPS · Shooter

Titanfall® 2
Shared: FPS · Action · Shooter

Call of Duty®
Shared: FPS · Action · Shooter

DOOM
Shared: Action · FPS · Shooter

METRO Last Light Redux
Shared: Action · FPS · Post-apocalyptic

Halo Infinite
Shared: FPS · Action · Shooter

Metro Exodus
Shared: FPS · Action · Post-apocalyptic

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

Warhammer 40,000: Boltgun
Shared: Boomer Shooter · FPS · Action

METRO 2033 Redux
Shared: FPS · Action · Post-apocalyptic

Aimlabs
Shared: FPS · Action · Shooter

RAGE
Shared: Action · FPS · Post-apocalyptic

Half-Life
Shared: FPS · Action · Shooter

Quake II
Shared: Boomer Shooter · Action · FPS

Fallout 4
Shared: Post-apocalyptic · Shooter · Action

Battlefield™ 2042
Shared: FPS · Action · Shooter

S.T.A.L.K.E.R. 2: Heart of Chornobyl - Standard Edition
Shared: FPS · Post-apocalyptic · Shooter

RoboCop: Rogue City
Shared: Action · FPS · First-Person

AMID EVIL
Shared: Boomer Shooter · FPS · Shooter

Half-Life: Opposing Force
Shared: Action · FPS · Shooter