Games like Peaceful Days
Games like Peaceful Days include Stardew Valley, DAVE THE DIVER, My Time at Portia, Sun Haven, and Graveyard Keeper. We matched them by the tags players give Peaceful Days on Steam (RPG, Indie, Simulation, Casual, and Farming Sim): closest matches first, and among equally close ones the better-known games.

Stardew Valley
Shared: RPG · Farming Sim · Pixel Graphics

DAVE THE DIVER
Shared: Casual · Pixel Graphics · RPG

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

Sun Haven
Shared: Farming Sim · RPG · Pixel Graphics

Graveyard Keeper
Shared: RPG · Simulation · Pixel Graphics

Coral Island
Shared: Farming Sim · Simulation · RPG

I Am Future: Cozy Apocalypse Survival
Shared: RPG · Casual · Farming Sim

Papers, Please
Shared: Indie · Simulation · Pixel Graphics

Touhou Mystia's Izakaya
Shared: RPG · Simulation · Casual

Fields of Mistria
Shared: RPG · Farming Sim · Pixel Graphics

Clanfolk
Shared: RPG · Farming Sim · Pixel Graphics

Emily is Away Too
Shared: Indie · Simulation · Casual

Farm Together
Shared: Simulation · Agriculture · Casual

Undertale
Shared: RPG · Pixel Graphics · Indie

Unpacking
Shared: Casual · Pixel Graphics · Simulation

To the Moon
Shared: Indie · Pixel Graphics · Story Rich

Yes, Your Grace
Shared: Indie · RPG · Pixel Graphics

Potion Craft: Alchemist Simulator
Shared: Simulation · Indie · Singleplayer

DELTARUNE
Shared: RPG · Pixel Graphics · Story Rich

Retirement Simulator
Shared: RPG · Simulation · Indie

STORY OF SEASONS: Friends of Mineral Town
Shared: Simulation · RPG · Farming Sim

Littlewood
Shared: Simulation · RPG · Pixel Graphics

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

Travellers Rest
Shared: RPG · Pixel Graphics · Farming Sim