Games like Poly Plaza
Games like Poly Plaza include Stardew Valley, My Time at Portia, Coral Island, Big Ambitions, and Infinity Nikki. We matched them by the tags players give Poly Plaza on Steam (Life Sim, Simulation, Sandbox, Capitalism, and Open World): closest matches first, and among equally close ones the better-known games.

Stardew Valley
Shared: Life Sim · Simulation · RPG

My Time at Portia
Shared: Life Sim · Open World · Simulation

Coral Island
Shared: Life Sim · Simulation · RPG

Big Ambitions
Shared: Simulation · Life Sim · Capitalism

Infinity Nikki
Shared: Open World · RPG · Simulation

The Sims™ 4
Shared: Life Sim · Simulation · Sandbox

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

Starsand Island
Shared: Life Sim · Sandbox · RPG

Factorio
Shared: Sandbox · Automation · Crafting

My Time at Sandrock
Shared: Life Sim · Sandbox · Crafting

Kenshi
Shared: Sandbox · Open World · RPG

Littlewood
Shared: Life Sim · Simulation · RPG

Satisfactory
Shared: Open World · Automation · Crafting

Disney Dreamlight Valley
Shared: Life Sim · Simulation · Sandbox

Clanfolk
Shared: Life Sim · Simulation · RPG

SPORE™
Shared: Sandbox · Simulation · Open World

Dyson Sphere Program
Shared: Automation · Simulation · Open World

Paralives
Shared: Life Sim · Simulation · Open World

Fields of Mistria
Shared: Life Sim · Simulation · RPG

Dinkum
Shared: Life Sim · Simulation · Sandbox

The Sims™ 3
Shared: Life Sim · Simulation · Sandbox

I Am Future: Cozy Apocalypse Survival
Shared: Simulation · RPG · Sandbox

Graveyard Keeper 2
Shared: Sandbox · Capitalism · Automation

Mon Bazou
Shared: Life Sim · Sandbox · Open World