Games like Castaway: Lost Horizon
Games like Castaway: Lost Horizon include Slime Rancher, DAVE THE DIVER, SPORE™, Yonder: The Cloud Catcher Chronicles, and Palia. We matched them by the tags players give Castaway: Lost Horizon on Steam (Casual, Adventure, Strategy, Colony Sim, and Farming Sim): closest matches first, and among equally close ones the better-known games.

Slime Rancher
Shared: Adventure · Exploration · Cute

DAVE THE DIVER
Shared: Casual · Adventure · Exploration

SPORE™
Shared: Colony Sim · Casual · Exploration

Yonder: The Cloud Catcher Chronicles
Shared: Adventure · Exploration · Farming Sim

Palia
Shared: Farming Sim · Exploration · Casual

Luma Island
Shared: Casual · Farming Sim · Adventure

Growtopia
Shared: Casual · Adventure · Exploration

My Time at Portia
Shared: Casual · Farming Sim · Adventure

Ratopia
Shared: Colony Sim · Strategy · Casual

Plants vs. Zombies GOTY Edition
Shared: Strategy · Casual · 2D

Terraria
Shared: Adventure · 2D · Exploration

Oxygen Not Included
Shared: Colony Sim · Strategy · 2D

12 Labours of Hercules
Shared: Casual · Strategy · Adventure

A Short Hike
Shared: Adventure · Exploration · Casual

The Forest
Shared: Adventure · Exploration · First-Person

Stardew Valley
Shared: Farming Sim · Casual · Agriculture

Garden Paws
Shared: Exploration · Farming Sim · Casual

The Promised Land
Shared: Casual · Strategy · Adventure

Out of Ore
Shared: Exploration · Farming Sim · Casual

The Long Dark
Shared: Exploration · Adventure · First-Person

Cult of the Lamb
Shared: Colony Sim · Cute · Adventure

Scribblenauts Unlimited
Shared: Casual · Adventure · 2D

Firewatch
Shared: Adventure · Exploration · Atmospheric

12 Labours of Hercules II: The Cretan Bull
Shared: Casual · Strategy · Adventure