Games like Starsand Island
Games like Starsand Island include Stardew Valley, My Time at Portia, Coral Island, My Time at Sandrock, and Palia. We matched them by the tags players give Starsand Island on Steam (Life Sim, Farming Sim, RPG, Building, and Casual): closest matches first, and among equally close ones the better-known games.

Stardew Valley
Shared: Farming Sim · Life Sim · RPG

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

Coral Island
Shared: Life Sim · Farming Sim · RPG

My Time at Sandrock
Shared: Life Sim · Farming Sim · Building

Palia
Shared: Life Sim · Farming Sim · Building

Dinkum
Shared: Farming Sim · Life Sim · Relaxing

Disney Dreamlight Valley
Shared: Life Sim · Relaxing · Sandbox

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

No Place Like Home
Shared: Farming Sim · RPG · Life Sim

Fields of Mistria
Shared: Farming Sim · Life Sim · RPG

Clanfolk
Shared: Farming Sim · Life Sim · RPG

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

Littlewood
Shared: Life Sim · RPG · Simulation

Luma Island
Shared: Farming Sim · Casual · Simulation

Travellers Rest
Shared: Life Sim · Farming Sim · RPG

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

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

Roots of Pacha
Shared: Farming Sim · Life Sim · RPG

Sun Haven
Shared: Farming Sim · Life Sim · RPG

PC Building Simulator
Shared: Building · Simulation · Sandbox

Infinity Nikki
Shared: RPG · Casual · Relaxing

Paralives
Shared: Life Sim · Building · Simulation

Farmer's Dynasty - Final Harvest Edition
Shared: Farming Sim · Life Sim · RPG

Kynseed
Shared: Farming Sim · Life Sim · RPG