Games like Merge Hero
Games like Merge Hero include Noita, Magicite, Megabonk, Vampire Survivors, and Streets of Rogue. We matched them by the tags players give Merge Hero on Steam (Idler, RPG, Roguelike, Survival, and Auto Battler): closest matches first, and among equally close ones the better-known games.

Noita
Shared: Roguelike · Pixel Graphics · Perma Death

Magicite
Shared: RPG · Roguelike · Action Roguelike

Megabonk
Shared: Roguelike · Action Roguelike · Survival

Vampire Survivors
Shared: Action Roguelike · Roguelite · Roguelike

Streets of Rogue
Shared: RPG · Action Roguelike · Roguelike

Sephiria
Shared: Roguelike · Action Roguelike · RPG

Hades
Shared: Action Roguelike · Roguelike · Roguelite

Moonlighter
Shared: Roguelike · RPG · Roguelite

Brotato
Shared: Roguelike · Action Roguelike · Survival

Stoneshard
Shared: RPG · Roguelike · Survival

Dead Cells
Shared: Roguelike · Action Roguelike · Pixel Graphics

Home Behind 2
Shared: RPG · Roguelike · Survival

Don't Starve
Shared: Survival · Crafting · Perma Death

Roguelands
Shared: Roguelike · RPG · Action Roguelike

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

Halls of Torment
Shared: Action Roguelike · Roguelike · Roguelite

SKYHILL
Shared: Survival · Action Roguelike · Roguelike

Everything is Crab: The Animal Evolution Roguelite
Shared: Action Roguelike · Survival · Roguelite

Despot's Game: Dystopian Battle Simulator
Shared: Roguelike · Auto Battler · RPG

Death Must Die
Shared: RPG · Action Roguelike · Roguelite

Hades II
Shared: Roguelike · RPG · Roguelite

Hero Siege
Shared: RPG · Action Roguelike · Roguelike

Death Road to Canada
Shared: Survival · Roguelike · Action Roguelike

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