Games like Frontier
Games like Frontier include Stardew Valley, Satisfactory, No Place Like Home, Fields of Mistria, and The Last Caretaker. We matched them by the tags players give Frontier on Steam (Farming Sim, Automation, Base Building, Action RPG, and Exploration): closest matches first, and among equally close ones the better-known games.

Stardew Valley
Shared: Farming Sim · Agriculture · RPG

Satisfactory
Shared: Automation · Base Building · Crafting

No Place Like Home
Shared: Farming Sim · Base Building · Crafting

Fields of Mistria
Shared: Farming Sim · Farming · RPG

The Last Caretaker
Shared: Base Building · Automation · Crafting

Forager
Shared: Farming Sim · Crafting · Base Building

Dinkum
Shared: Farming Sim · Agriculture · Farming

Factorio
Shared: Automation · Base Building · Crafting

Enshrouded
Shared: Base Building · Crafting · Exploration

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

StarRupture
Shared: Automation · Base Building · Exploration

The Riftbreaker
Shared: Base Building · Action RPG · Exploration

Rusty's Retirement
Shared: Farming Sim · Automation · Farming

Sun Haven
Shared: Farming Sim · RPG · Crafting

Dyson Sphere Program
Shared: Automation · Base Building · Sci-fi

Lightyear Frontier
Shared: Farming Sim · Base Building · Automation

FOUNDRY
Shared: Automation · Base Building · Crafting

Autonauts
Shared: Automation · Base Building · Crafting

Abiotic Factor
Shared: Base Building · Crafting · Exploration

The Planet Crafter
Shared: Base Building · Crafting · Automation

Coral Island
Shared: Farming Sim · Agriculture · Crafting

DAVE THE DIVER
Shared: Exploration · Farming Sim · Pixel Graphics

Return from Core
Shared: Automation · Base Building · Crafting

Core Keeper
Shared: Exploration · Base Building · Crafting