Games like Operation: Outbreak Idle

Hardcore open-world survival where preparation is everything. Scavenge, craft, fortify during the day. When night falls, the infected hunt in numbers. Play solo or with friends in a brutal post-apocalyptic sandbox where survival is earned through smart decisions. How many Nights will you survive?

Build your base on a moving Machine, travel through biomes with different resources, and prepare for the night when a zombie threat is much higher than during the day. Would you go solo or explore this new world with your best friends?

Build your towers and let them do the killing! Connect 12 unique towers through the Reactor to discover 144 devastating synergies. Kill endless zombie hordes, mutate them for bigger rewards, and push your build to the limit in a chaotic bullet hell.

This is a multiplayer cooperative open world construction survival sandbox game, where you and your friends must find supplies and build shelters in this world. You have to keep an eye on your character's needs state at all times, a bad state is likely to lead to death.

Defend. Upgrade. Dominate. A relaxing incremental base-defense game, packed with powerful skills and a deep skill tree.

The Front is a survival open-world crafting sandbox game. You are a resistance fighter sent back in time to stop the rise of a tyrannical empire. Collect resources, craft tech, build shelters, and fight monsters to accomplish your mission.

The Horde is coming, but you're ready to fight it! Assemble your squad, choose their upgrades, and build powerful synergies against thousands of undead. Survive. Then evolve. Then break every limit in this deceptively simple but addictive bullet heaven game.

Build twisting mazes with tetromino blocks and deploy unique towers in this strategic roguelite tower defense adventure!

HumanitZ is an isometric, open-world sandbox survival game set in a world ended by a zombie outbreak. Survive alone or with friends by scavenging, crafting, building, and fighting to last as long as ‘humanly’ possible. You can’t change the past, but you can fight for the future of humanity.

No More Room in Hell 2 is an intense 8 player zombie shooter. Overcome the endless undead. Avoid infection. Survive hell together.

A short incremental siege game centered around growing and strengthening an army to defend your kingdom. Seize the crown from an endless wave of enemies for your best chance at survival!

Mine by day, defend by night. Master 25+ spells, sell rare ores for gear upgrades, and grow stronger each run in this procedurally generated roguelite tower defense. Enjoy full controller and Steam Deck support.

Fight hordes and defend your Stronghold in a bullet heaven survivor-like with co-op and tower defense. Gain power-ups every level, collect random artifacts from chests and grow stronger to survive, defeat the boss and claim a top spot on the Sineus Arena leaderboards!

Become a crew member of an Interdimensional Express Train! Discover a new world full of mysterious creatures, enemies and places. Upgrade and customize your train, gather new materials and build better weapons. Play solo or online сo-op with up to 4 people.

Into the Radius 2 is an immersive VR survival shooter, set in a realm of surreal landscapes and deadly entities known as Pechorsk Anomaly. Arm yourself with realistic weapons and venture deeper into the mysteries within. Featuring co‑op for up to four players.

Open world zombie survival Coop game with base building, looting, crafting, vehicles, and exploration.

Build and manage your own castle settlement in a land reclaimed by wilderness. With detailed management, survival strategy, and a moddable sandbox world, Going Medieval challenges you to build the mightiest colony this side of the apocalypse.

A corner screen incremental brick-breaker where bouncing cores destroy endless swarms. Let it run in the corner of your screen while you work or jump into fullscreen and take control yourself. Unlock new Cores, expand your skill tree, survive endless waves.