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.

Trapped in the twisted game room of a mysterious entity, Dealer's Dice is a high-stakes roguelike dice-defense game. Collect powerful dice, manage your betting table, and gamble against relentless waves of invaders. Push your luck, test your greed, and survive.

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.

You have only 5 minutes to stylishly explode your way through the hordes of corrupted entities in a retro FPS, roguelike liminal-nightmare... and Timmee is here to help!

You are a disease. Infect the human body as a lone pathogen in this cellular roguelike shooter. Collect organelles to evolve your parasite in a microscopic arms race against your host's immune system. Conquer a beautiful, procedurally generated world of tiny proportions.

RoundZ is a solo-developed round-based survival zombie game, with each round becoming progressively harder as the zombies get more health and in bigger waves. 

Fortress Fury is a survivor multiplayer tower defense roguelite. Endless hordes of enemies want to crush your tower! Buy weapons and upgrades to craft an array of overpowering builds. Will you be able to survive all waves and be the last tower?

In Call of Duty®: Black Ops 7, Treyarch and Raven Software are bringing players the biggest Black Ops ever across an innovative Co-Op Campaign, an electrifying Multiplayer experience, and the legendary Round-Based Zombies mode.

Welcome to UMAN - Become a cog in the machine - Work, sleep and don't ask questions - Collect your trash, hit your quota, consume, upgrade and meet your coworkers. But whatever you do... don't look into the eyes.

The Perfect Tower II is a mix between an incremental and a tower defense game. Build a town, manage resources and explore a variety of mini-games and tons of upgrades. Fully automate your game and watch numbers going up!

Jump into this free‑to‑play looter‑shooter RPG featuring tactical combat, deep progression, and an exclusive canon storyline, playable solo or with friends.

On RuneScape's forgotten continent of Ashenfall, dragons have awoken. Gather, build, skill and craft in this co-operative survival adventure. Only by mastering survival and uncovering ancient secrets can you hope to face the ferocious Dragon Queen.

Drive, ram, and blast through endless zombie hordes in a top-down vehicular action game, then upgrade your weapons, unlock brutal war machines, and carry your growing arsenal into the next run.

A first-person shooter meets quarantine inspection in post-apocalyptic Chicago. You’ve got 30 days until the army arrives. Hold out, fix your car, and fight your way through Chicago to the main checkpoint to save your little brother.

From a small village of a dozen people to a small kingdom of thousands of people. Arrange for residents to work, gathering, fishing and hunting, farming and mining, processing and manufacturing. Trade, accumulate supplies, increase your strength, and fight evil forces and monsters.

Guard your campfire through the night and feed your rivals' rifts with monsters. A multiplayer tower-defense survival hybrid where deck building, base building, and dueling economies decide who survives and who freezes.

Winter Survival is a story-driven survival game where trauma turns reality into a reflection of your breaking mind. Battle cold, hunger, hallucinations, and adapt to the wilderness as it adapts to you.

Whack-A-Monster. An incremental game about Whacking, Smashing, Splashing & BONKING monsters. Upgrade through the skill tree and unlock new weapons to vanquish all evil from this world.

A dynamic platformer with lots of blood and chaotic shooting. Unleash your desire for violence by killing crowds of enemies, hastily injecting yourself with another dose of experimental drug.

Embark on your creative journey of vehicle design, as you create and operate vehicles to survive this dangerous open world. Anymaker is a detailed and technical vehicle builder and survival game. Design your chassis, build your engine, connect components, and travel into the unknown.