Single-player games like Under A New Sun
Below are 9 single-player Steam games similar to Under A New Sun, ranked by player overlap. Every pick carries Steam's Single-player category, so multiplayer-only titles or always-online games don't sneak in. imho.run pulls the category data from Steam directly — Single-player here matches what the store labels.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like Under A New Sun page.
Ranked picks
- 1

Project Castaway
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Adventure with Under A New Sun.
Project Castaway is a survival crafting title set in the Pacific Ocean. Live the life of a stranded castaway, with only yourself - and the island's inhabitants - for company! Sail the ocean, hunt, explore unique islands and gather resources as you fight for survival.
- 2

Satisfactory
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Indie and Adventure with Under A New Sun.
Satisfactory is a first-person open-world factory building game with a dash of exploration and combat. Play alone or with friends, explore an alien planet, create multi-story factories, and enter conveyor belt heaven!
- 3

Valheim
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Indie and Adventure with Under A New Sun.
A brutal exploration and survival game for 1-10 players, set in a procedurally-generated purgatory inspired by viking culture. Battle, build, and conquer your way to a saga worthy of Odin’s patronage!
- 4

Green Hell
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Indie and Adventure with Under A New Sun.
Plunge into the open-world survival simulation set in the extreme conditions of the uncharted Amazon jungle. Use real-life survival techniques to craft, hunt, fight, and gather resources, set a makeshift shelter, or raise a fortress. Survive alone or team up with your friends and challenge the jungle together.
- 5

Sunkenland
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Indie and Early Access with Under A New Sun.
Get ready for a Waterworld-themed survival game with modular base building, sunken city scavenging, crafting, base defense, and invasions of NPC clans for resources and territory. Ready for the water apocalypse?
- 6

Soulmask
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Indie and Adventure with Under A New Sun.
Don the Ancient Mask. Wield the power of gods. Possess any of your tribespeople, recruit followers, and build a thriving automated civilization. Survive, expand, and forge your own legacy across a vast ancient open world — together with friends.
- 7

Stranded Deep
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Indie and Adventure with Under A New Sun.
Take the role of a plane crash survivor stranded somewhere in the Pacific Ocean. Come face to face with some of the most life threatening scenarios that will result in a different experience each time you play. Scavenge. Discover. Survive.
- 8

Raft
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Indie and Adventure with Under A New Sun.
Raft™ throws you and your friends into an epic oceanic adventure! Alone or together, players battle to survive a perilous voyage across a vast sea! Gather debris, scavenge reefs and build your own floating home, but be wary of the man-eating sharks!
- 9

Survival: Fountain of Youth
Single-player alternative to Under A New Sun — playable solo, no multiplayer required. Shares Indie and Adventure with Under A New Sun.
Survival: Fountain of Youth is a challenging single-player open-world adventure game set on the Caribbean islands. Survive as a shipwrecked 16th-century explorer, craft tools and shelter, and uncover the secrets of both an ancient civilization and your own fate.