Games like Moonbase 332
Games like Moonbase 332 include Serious Sam 3: BFE, Serious Sam II, KovaaK's, Starship Troopers: Extermination, and SUPERHOT. We matched them by the tags players give Moonbase 332 on Steam (Action, Indie, Comedy, FPS, and Arcade): closest matches first, and among equally close ones the better-known games.

Serious Sam 3: BFE
Shared: Action · FPS · Comedy

Serious Sam II
Shared: Action · FPS · Comedy

KovaaK's
Shared: Action · Indie · FPS

Starship Troopers: Extermination
Shared: Action · FPS · First-Person

SUPERHOT
Shared: Action · FPS · Indie

Bright Memory: Infinite
Shared: Action · Indie · FPS

Aimlabs
Shared: FPS · Action · First-Person

Black Mesa
Shared: Action · FPS · First-Person

Shadow Warrior
Shared: Action · FPS · Comedy

Anger Foot
Shared: FPS · Action · Arcade

Dino D-Day
Shared: Action · Indie · FPS

Borderlands 2
Shared: Action · FPS · Comedy

Call of Juarez: Gunslinger
Shared: Action · FPS · Comedy

Serious Sam HD: The First Encounter
Shared: Action · FPS · Comedy

Borderlands: The Pre-Sequel
Shared: Action · FPS · Comedy

Serious Sam Fusion 2017 (beta)
Shared: Action · FPS · Indie

Serious Sam Classics: Revolution
Shared: Action · FPS · Indie

MULLET MADJACK
Shared: FPS · Action · Arcade

Call of Duty®
Shared: FPS · Action · First-Person

Counter-Strike
Shared: Action · FPS · First-Person

Half-Life 2
Shared: Action · FPS · First-Person

BioShock Infinite
Shared: Action · FPS · First-Person

Devil Daggers
Shared: Indie · FPS · Action

Serious Sam 4
Shared: Action · FPS · Comedy

