Games like Over 9000 Zombies!
Games like Over 9000 Zombies! include Enter the Gungeon, Death Road to Canada, Hero Siege, Left 4 Dead 2, and Risk of Rain 2. We matched them by the tags players give Over 9000 Zombies! on Steam (Action Roguelike, Zombies, Multiplayer, Twin Stick Shooter, and Tower Defense): closest matches first, and among equally close ones the better-known games.

Enter the Gungeon
Shared: Action Roguelike · Pixel Graphics · Multiplayer

Death Road to Canada
Shared: Zombies · Action Roguelike · Pixel Graphics

Hero Siege
Shared: Action Roguelike · Multiplayer · Pixel Graphics

Left 4 Dead 2
Shared: Zombies · Multiplayer · Co-op

Risk of Rain 2
Shared: Action Roguelike · Multiplayer · Co-op

Brotato
Shared: Action Roguelike · Multiplayer · Roguelike

Vampire Survivors
Shared: Action Roguelike · Pixel Graphics · Roguelike

Wizard of Legend
Shared: Action Roguelike · Pixel Graphics · Multiplayer

The Binding of Isaac: Rebirth
Shared: Action Roguelike · Roguelike · Pixel Graphics

Streets of Rogue
Shared: Action Roguelike · Multiplayer · Pixel Graphics

Children of Morta
Shared: Multiplayer · Action Roguelike · Pixel Graphics

Nuclear Throne
Shared: Action Roguelike · Pixel Graphics · Roguelike

Project Zomboid
Shared: Zombies · Multiplayer · Survival

Terraria
Shared: Multiplayer · Survival · Pixel Graphics

Broforce
Shared: Co-op · Multiplayer · Pixel Graphics

Risk of Rain (2013)
Shared: Action Roguelike · Roguelike · Pixel Graphics

7 Days to Die
Shared: Zombies · Multiplayer · Survival

Relic Hunters Zero: Remix
Shared: Twin Stick Shooter · Action Roguelike · Co-op

Ravenswatch
Shared: Action Roguelike · Co-op · Multiplayer

Necrosmith
Shared: Action Roguelike · Zombies · Tower Defense

Sephiria
Shared: Action Roguelike · Co-op · Roguelike

Megabonk
Shared: Action Roguelike · Roguelike · Survival

Crab Champions
Shared: Action Roguelike · Multiplayer · Co-op

Left 4 Dead
Shared: Zombies · Multiplayer · Co-op