Games like Rock'n Cow
Games like Rock'n Cow include Left 4 Dead 2, PUBG: BATTLEGROUNDS, Call to Arms - Gates of Hell: Ostfront, Aliens: Dark Descent, and The Last Stand: Aftermath. We matched them by the tags players give Rock'n Cow on Steam (Beat 'em up, Top-Down Shooter, Strategy, Real Time Tactics, and Zombies): closest matches first, and among equally close ones the better-known games.

Left 4 Dead 2
Shared: Zombies · Action · Shooter

PUBG: BATTLEGROUNDS
Shared: Shooter · Survival · Action

Call to Arms - Gates of Hell: Ostfront
Shared: Strategy · Real Time Tactics · PvE

Aliens: Dark Descent
Shared: Strategy · Real Time Tactics · Action

The Last Stand: Aftermath
Shared: Top-Down Shooter · Zombies · Survival

Police Stories
Shared: Strategy · Action · Top-Down Shooter

Escape From Duckov
Shared: Top-Down Shooter · Action · Shooter

Plants vs. Zombies GOTY Edition
Shared: Strategy · Zombies · 2D

Days Gone
Shared: Zombies · Action · Survival

Back 4 Blood
Shared: Zombies · Action · Shooter

They Are Billions
Shared: Strategy · Zombies · Survival

DayZ
Shared: Zombies · Survival · Shooter

Project Zomboid
Shared: Zombies · Survival · Building

Yet Another Zombie Defense HD
Shared: Top-Down Shooter · Zombies · Strategy

Door Kickers
Shared: Strategy · Action · Real Time Tactics

The Last of Us™ Part I
Shared: Zombies · Shooter · Action-Adventure

Arma Reforger
Shared: Strategy · Action · Shooter

12 is Better Than 6
Shared: Top-Down Shooter · Action · Shooter

Left 4 Dead
Shared: Zombies · Action · Shooter

The Forest
Shared: Survival · Building · Action

World War Z
Shared: Zombies · Action · PvE

Call of Duty®: Black Ops III
Shared: Zombies · Action · Shooter

Halo: Spartan Assault
Shared: Top-Down Shooter · Action · Strategy