Games like Zombie Smash
Games like Zombie Smash include Timberman, Vampire Survivors, Dungeon Munchies, Cookie Clicker, and UFO 50. We matched them by the tags players give Zombie Smash on Steam (Action, RPG, Arcade, Incremental, and Collectathon): closest matches first, and among equally close ones the better-known games.

Timberman
Shared: Action · Pixel Graphics · Arcade

Vampire Survivors
Shared: Pixel Graphics · 2D · Action

Dungeon Munchies
Shared: Action · RPG · Pixel Graphics

Cookie Clicker
Shared: Incremental · Pixel Graphics · Collectathon

UFO 50
Shared: Action · Arcade · Pixel Graphics

The Escapists
Shared: Pixel Graphics · Action · 2D

Terraria
Shared: 2D · Pixel Graphics · Survival

Broforce
Shared: Action · Pixel Graphics · 2D

The Final Station
Shared: Pixel Graphics · Action · 2D

Shower With Your Dad Simulator 2015: Do You Still Shower With Your Dad
Shared: Arcade · 2D · Action

Undertale
Shared: RPG · Pixel Graphics · Funny

DELTARUNE
Shared: RPG · Pixel Graphics · Funny

Halls of Torment
Shared: Action · Pixel Graphics · RPG

BALL x PIT
Shared: Action · Arcade · Pixel Graphics

Hotline Miami
Shared: Action · Pixel Graphics · Top-Down

UnderMine
Shared: RPG · Action · Pixel Graphics

South Park™: The Stick of Truth™
Shared: RPG · Action · Funny

The Mageseeker: A League of Legends Story™
Shared: RPG · 2D · Pixel Graphics

Rogue Legacy 2
Shared: Arcade · Action · RPG

Turnip Boy Commits Tax Evasion
Shared: RPG · Action · Top-Down

Hyper Light Drifter
Shared: Action · Pixel Graphics · RPG

ZED ZONE
Shared: Action · Pixel Graphics · Survival

Dead Pixels
Shared: Action · Pixel Graphics · 2D

Hero Siege
Shared: RPG · Pixel Graphics · Action