Games like Operation Singularity
Games like Operation Singularity include Halo: Spartan Assault, Chicken Invaders Universe, CS2D, Planes, Bullets and Vodka, and Zombieville USA 3D. We matched them by the tags players give Operation Singularity on Steam (Action, Casual, Arcade, Shooter, and Top-Down Shooter): closest matches first, and among equally close ones the better-known games.

Halo: Spartan Assault
Shared: Action · Top-Down Shooter · Shooter

Chicken Invaders Universe
Shared: Action · Shooter · Top-Down Shooter

CS2D
Shared: Action · Shooter · Casual

Planes, Bullets and Vodka
Shared: Action · Casual · Arcade

Zombieville USA 3D
Shared: Action · Arcade · Shooter

Metal Slug: Awakening
Shared: Arcade · Casual · Shooter

Deployment
Shared: Action · Top-Down Shooter · Shooter

HELLDIVERS™ Dive Harder Edition
Shared: Action · Top-Down Shooter · Twin Stick Shooter

BALL x PIT
Shared: Action · Arcade · Top-Down Shooter

Cyberhunt
Shared: Action · Casual · Arcade

Escape From Duckov
Shared: Action · Top-Down Shooter · Shooter

MARVEL Tōkon: Fighting Souls
Shared: Action · Casual · Arcade

Sky Force Reloaded
Shared: Arcade · Action · Top-Down Shooter

Sektori
Shared: Arcade · Twin Stick Shooter · Top-Down Shooter

BioShock Infinite
Shared: Action · Shooter · Fantasy

SYNTHETIK: Legion Rising
Shared: Action · Top-Down Shooter · Shooter

Battlefield™ 2042
Shared: Shooter · Action · Combat

DJMAX RESPECT V
Shared: Casual · Action · Arcade

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

Renegade Ops
Shared: Action · Arcade · Twin Stick Shooter

UpGun
Shared: Casual · Shooter · Arcade

ACE COMBAT™ 7: SKIES UNKNOWN
Shared: Arcade · Shooter · Action

The Ascent
Shared: Action · Top-Down Shooter · Shooter

The Hong Kong Massacre
Shared: Action · Top-Down Shooter · Shooter

