55%Good matchUltimate Zombie Defense
86%1k86% positive reviews, Very Positive across 1k reviews·Zombies · Tower Defense
—






Command automated military defenses, upgrade your fortress, and survive massive zombie waves in this action-packed idle defense game. Build powerful defenses, unlock upgrades, and hold the line against endless undead hordes.
Operation: Outbreak Idle
Steam
Use bullet points:
Explain: Fight → earn resources → upgrade → automate → survive longer.
Steam data © 2026 Valve Corporation. Trademarks are property of their respective owners.
All matches
Finding similar games…
Ultimate Zombie DefenseShares Shooter · Survival · Zombies , adds Community tag: Online Co-Op86% · 1k positive reviews55%Good match—
Yet Another Zombie SurvivorsShares Bullet Hell · Survival · Zombies , adds Action Roguelike94% · 5k positive reviews54%Good match—
Deadly DaysShares Survival · Zombies , adds Roguelite86% · 1k positive reviews53%Good match—
Zombie Cure LabShares Survival · Zombies , adds Colony Sim68% · 355 positive reviews53%Good match—
Samawa IdleShares Colorful · Stylized · Idler , adds Clicker66% · 386 positive reviews53%Good match—
Ultimate Zombie Defense 2Shares Zombies , adds Survival Horror79% · 461 positive reviews52%Good match—All matches
The best games like Operation: Outbreak Idle are Ultimate Zombie Defense, Yet Another Zombie Survivors, Deadly Days, Zombie Cure Lab, and Samawa Idle.
Match on: filter matches for Operation: Outbreak Idle by tag