Games like Mutation Madness
Games like Mutation Madness include HELLDIVERS™ 2, Grand Theft Auto V Legacy, Warhammer 40,000: Space Marine 2, Just Cause™ 3, and ARC Raiders. We matched them by the tags players give Mutation Madness on Steam (Action, Third-Person Shooter, Shooter, Casual, and Arcade): closest matches first, and among equally close ones the better-known games.

HELLDIVERS™ 2
Shared: Third-Person Shooter · Action · Shooter

Grand Theft Auto V Legacy
Shared: Action · Shooter · Third-Person Shooter

Warhammer 40,000: Space Marine 2
Shared: Action · Third-Person Shooter · PvE

Just Cause™ 3
Shared: Action · Third-Person Shooter · Shooter

ARC Raiders
Shared: Third-Person Shooter · Shooter · PvE

Plants vs. Zombies: Battle for Neighborville™
Shared: Third-Person Shooter · Shooter · Casual

Warframe
Shared: Third-Person Shooter · Action · Third Person

PUBG: BATTLEGROUNDS
Shared: Shooter · Third-Person Shooter · Action

STAR WARS™ Battlefront™ II
Shared: Shooter · Third-Person Shooter · Action

EARTH DEFENSE FORCE 6
Shared: Action · Third-Person Shooter · Shooter

Max Payne 3
Shared: Action · Third-Person Shooter · Shooter

Hitman: Absolution
Shared: Action · Third-Person Shooter · Shooter

STAR WARS™ Battlefront II (Classic, 2005)
Shared: Action · Shooter · Third-Person Shooter

The Mean Greens - Plastic Warfare
Shared: Action · Third-Person Shooter · Shooter

Vanquish
Shared: Action · Third-Person Shooter · Shooter

Tomb Raider Game of the Year
Shared: Action · Third-Person Shooter · Singleplayer

Warhammer 40,000: Space Marine - Anniversary Edition
Shared: Action · Third-Person Shooter · Shooter

Just Cause 2
Shared: Action · Third-Person Shooter · Shooter

Grand Theft Auto IV: The Complete Edition
Shared: Action · Third-Person Shooter · Singleplayer

Call of Duty®: Modern Warfare® II
Shared: Action · Shooter · Third-Person Shooter

Marvel Rivals
Shared: Third-Person Shooter · Action · Shooter

Tom Clancy's Ghost Recon® Wildlands
Shared: Shooter · Action · Singleplayer

World War Z
Shared: Action · Shooter · Third-Person Shooter

The Callisto Protocol™
Shared: Third-Person Shooter · Shooter · Action