Games like Mini Merchant
Games like Mini Merchant include Terraria, Tactical Breach Wizards, Turnip Boy Commits Tax Evasion, 江湖十一, and Kenshi. We matched them by the tags players give Mini Merchant on Steam (RPG, Puzzle, Sandbox, Strategy RPG, and Turn-Based Strategy): closest matches first, and among equally close ones the better-known games.

Terraria
Shared: Sandbox · 2D · Exploration

Tactical Breach Wizards
Shared: Puzzle · Turn-Based Strategy · Strategy RPG

Turnip Boy Commits Tax Evasion
Shared: Puzzle · RPG · Exploration

江湖十一
Shared: RPG · Sandbox · Exploration

Kenshi
Shared: Sandbox · RPG · Strategy RPG

The Last Spell
Shared: RPG · Turn-Based Strategy · Strategy RPG

Dorfromantik
Shared: Puzzle · Turn-Based Strategy · Sandbox

Stardew Valley
Shared: RPG · Sandbox · Pixel Graphics

Word Game
Shared: Puzzle · RPG · Exploration

Elin
Shared: RPG · Sandbox · Dungeon Crawler

Niche - a genetics survival game
Shared: Puzzle · Turn-Based Strategy · RPG

Caves of Lore
Shared: RPG · Strategy RPG · Dungeon Crawler

Pathway
Shared: Strategy RPG · RPG · Exploration

Noita
Shared: Sandbox · Dungeon Crawler · Pixel Graphics

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

Into the Breach
Shared: Turn-Based Strategy · Puzzle · Turn-Based Tactics

Your Only Move Is HUSTLE
Shared: Turn-Based Strategy · Sandbox · Turn-Based Tactics

The Scroll of Taiwu : Beyond The Dome
Shared: RPG · Sandbox · Indie

Fell Seal: Arbiter's Mark
Shared: RPG · Turn-Based Strategy · Strategy RPG

Slice & Dice
Shared: Turn-Based Strategy · RPG · Dungeon Crawler

The Banner Saga
Shared: RPG · Strategy RPG · Turn-Based Strategy

Symphony of War: The Nephilim Saga
Shared: RPG · Turn-Based Strategy · Strategy RPG

Low Magic Age
Shared: Turn-Based Strategy · Dungeon Crawler · Turn-Based Tactics

The Matchless Kungfu
Shared: RPG · Sandbox · Exploration