Games like Outbreak: The New Nightmare
Games like Outbreak: The New Nightmare include Dying Light, Dead by Daylight, Left 4 Dead 2, Resident Evil 2, and Resident Evil 3. We matched them by the tags players give Outbreak: The New Nightmare on Steam (Survival Horror, Online Co-Op, Multiplayer, Horror, and Zombies): closest matches first, and among equally close ones the better-known games.

Dying Light
Shared: Survival Horror · Online Co-Op · Zombies

Dead by Daylight
Shared: Survival Horror · Multiplayer · Horror

Left 4 Dead 2
Shared: Zombies · Multiplayer · Online Co-Op

Resident Evil 2
Shared: Survival Horror · Zombies · Horror

Resident Evil 3
Shared: Horror · Zombies · Survival Horror

Escape the Backrooms
Shared: Online Co-Op · Multiplayer · Horror

Outlast
Shared: Survival Horror · Horror · Multiplayer

Resident Evil Revelations 2
Shared: Survival Horror · Multiplayer · Horror

Back 4 Blood
Shared: Online Co-Op · Multiplayer · Zombies

DEVOUR
Shared: Online Co-Op · Survival Horror · Horror

Resident Evil Village
Shared: Survival Horror · Horror · Action

Resident Evil 4
Shared: Survival Horror · Horror · Action

Resident Evil 7 Biohazard
Shared: Survival Horror · Horror · Zombies

No More Room in Hell 2
Shared: Online Co-Op · Multiplayer · Survival Horror

Backrooms: Escape Together
Shared: Multiplayer · Online Co-Op · Horror

Resident Evil 5
Shared: Online Co-Op · Zombies · Action

Outlast 2
Shared: Survival Horror · Horror · Multiplayer

Killing Floor 2
Shared: Multiplayer · Online Co-Op · Zombies

DayZ
Shared: Online Co-Op · Multiplayer · Zombies

Resident Evil 6
Shared: Zombies · Action · Online Co-Op

Inside the Backrooms
Shared: Survival Horror · Multiplayer · Horror

Killing Floor
Shared: Zombies · Horror · Multiplayer

Pacify
Shared: Online Co-Op · Horror · Multiplayer

Halloween: The Game
Shared: Multiplayer · Horror · Survival Horror