Games like Zombie Apocalypse 2021
Games like Zombie Apocalypse 2021 include Escape From Duckov, Bit Blaster XL, Planes, Bullets and Vodka, Cyberhunt, and Exit the Gungeon. We matched them by the tags players give Zombie Apocalypse 2021 on Steam (Action, Adventure, Shooter, Casual, and Shoot 'Em Up): closest matches first, and among equally close ones the better-known games.

Escape From Duckov
Shared: Action · Adventure · Shooter

Bit Blaster XL
Shared: Shooter · Shoot 'Em Up · Action

Planes, Bullets and Vodka
Shared: Action · Casual · Shoot 'Em Up

Cyberhunt
Shared: Action · Adventure · Casual

Exit the Gungeon
Shared: Action · Adventure · Arcade

Sonic Superstars
Shared: Action · Adventure · Casual

Broforce
Shared: Action · Shooter · Platformer

Sonic Origins
Shared: Action · Adventure · 2D Platformer

Rogue Legacy 2
Shared: Action · Arcade · Adventure

Commando Collection
Shared: Action · Shooter · Arcade

BEEP
Shared: Adventure · Platformer · Action

BALL x PIT
Shared: Action · Arcade · Shoot 'Em Up

Grand Theft Auto V Legacy
Shared: Action · Shooter · Adventure

Pikuniku
Shared: Adventure · Casual · Action

Alex Jones: NWO Wars
Shared: Action · Shooter · Arcade

Zombotron
Shared: Action · Adventure · Shooter

Nova Drift
Shared: Shoot 'Em Up · Arcade · Bullet Hell

Airscape - The Fall of Gravity
Shared: Shoot 'Em Up · Casual · Platformer

Twin Shot Deluxe
Shared: Action · Casual · Arcade

Cuphead
Shared: Platformer · Cartoon · Action

Revolution Ace
Shared: Action · Shoot 'Em Up · Shooter

SANABI
Shared: Action · Adventure · 2D Platformer

TouHou Makuka Sai ~ Fantastic Danmaku Festival
Shared: Action · Adventure · Casual

LUFTRAUSERS
Shared: Action · Arcade · Bullet Hell