Games like Merge Me!
Games like Merge Me! include Stardew Valley, WorldBox - God Simulator, Graveyard Keeper, IdleOn - The Incremental MMO, and SPORE™. We matched them by the tags players give Merge Me! on Steam (Simulation, Idler, God Game, RPG, and Colony Sim): closest matches first, and among equally close ones the better-known games.

Stardew Valley
Shared: Farming Sim · Simulation · RPG

WorldBox - God Simulator
Shared: Simulation · God Game · Sandbox

Graveyard Keeper
Shared: Simulation · RPG · Pixel Graphics

IdleOn - The Incremental MMO
Shared: Idler · RPG · Pixel Graphics

SPORE™
Shared: God Game · Simulation · Colony Sim

Potion Craft: Alchemist Simulator
Shared: Simulation · Crafting · Management

Clanfolk
Shared: Simulation · Farming Sim · RPG

Kingdoms and Castles
Shared: Simulation · Colony Sim · Sandbox

Rusty's Retirement
Shared: Idler · Simulation · Farming Sim

Fields of Mistria
Shared: Farming Sim · RPG · Simulation

Prison Architect
Shared: Simulation · Colony Sim · Sandbox

Banished
Shared: Simulation · Colony Sim · Sandbox

DAVE THE DIVER
Shared: Pixel Graphics · Management · Simulation

Amazing Cultivation Simulator
Shared: Simulation · RPG · Sandbox

RimWorld
Shared: Colony Sim · Simulation · Sandbox

鬼谷八荒 Tale of Immortal
Shared: Simulation · RPG · Sandbox

Oxygen Not Included
Shared: Colony Sim · Simulation · Sandbox

Coral Island
Shared: Simulation · Farming Sim · RPG

My Time at Portia
Shared: RPG · Simulation · Farming Sim

Kenshi
Shared: RPG · Sandbox · Simulation

Foundation
Shared: Simulation · Sandbox · Management

The Universim
Shared: God Game · Colony Sim · Sandbox

Dwarf Fortress
Shared: Simulation · Colony Sim · Sandbox

Crusader Kings III
Shared: Simulation · RPG · Strategy