Single-player games like Rainbow Billy: The Curse of the Leviathan
Below are 13 single-player Steam games similar to Rainbow Billy: The Curse of the Leviathan, 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 Rainbow Billy: The Curse of the Leviathan page.
Ranked picks
- 1

Rizz Dungeon: Skeleton Key to My Heart
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and Adventure with Rainbow Billy: The Curse of the Leviathan.
Fighting is hard, right? Let your party do it for you! Romance Monster Girls and traverse the Dungeon! Hopefully they'll all get along... right?
- 2

Pocket Pawns
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and Adventure with Rainbow Billy: The Curse of the Leviathan.
Catch wild chess pieces by solving checkmate puzzles, build your team and explore nine towns in a chess RPG. Collect 272 pieces and 589 boards, learn with 202 lessons, and challenge six Club Masters on your way to the World Championship.
- 3

Stories of Somnia
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and Adventure with Rainbow Billy: The Curse of the Leviathan.
Stories of Somnia is an exploration-first JRPG with the bones of a Metroidvania. Use spells to grapple across gaps, change the rules of combat, and reshape the world around you. Collect memory-born companions called Dreamkin and uncover a story about grief, time, and the courage to rest.
- 4

People of Note
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares RPG with Rainbow Billy: The Curse of the Leviathan.
In this turn-based RPG musical, join Cadence as she recruits an ensemble of musicians on her quest for stardom. Experience turn-based combat like never before, where each battle is a musical performance with evolving combat conditions and genre-bending mashup attacks!
- 5

Mythic Mire
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and Adventure with Rainbow Billy: The Curse of the Leviathan.
A surreal RPG-adventure set in a world between dreams and nightmares. Explore strange environments with your trusty digital Pixie companions.
- 6

HALF-BAKED GIRLS
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and Adventure with Rainbow Billy: The Curse of the Leviathan.
This is the tale of two girls, trapped in a dark mansion with no easy way out. They must battle evil spirits and encounter friendly ghosts to grow strong enough to uncover the truth that lurks within...
- 7

Siralim Ultimate
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and RPG with Rainbow Billy: The Curse of the Leviathan.
Siralim Ultimate is a monster-catching, dungeon-crawling RPG with a ridiculous amount of depth. Summon over 1200 different creatures and travel through randomly generated dungeons to acquire resources, new creatures, and loot.
- 8

Planet Stronghold 2
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and RPG with Rainbow Billy: The Curse of the Leviathan.
Planet Stronghold 2 is the sequel to the first sci-fi VN/RPG made by Winter Wolves. Isometric map exploration, crafting, combat, a branching plot and of course romances awaits you in this new adventure!
- 9

Undertale
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and RPG with Rainbow Billy: The Curse of the Leviathan.
UNDERTALE! The RPG game where you don't have to destroy anyone.
- 10

DELTARUNE
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and RPG with Rainbow Billy: The Curse of the Leviathan.
Dive into the parallel story to UNDERTALE! Fight or spare your way through action-packed battles as you explore a mysterious world alongside an endearing cast of new and familiar characters. Chapters 1-4 will be available on launch, with more planned as free updates!
- 11

The Caribou Trail
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and Adventure with Rainbow Billy: The Curse of the Leviathan.
The WWI story where your goal isn’t to kill, but to survive. In the still trenches, three soldiers learn the harsh truth of war: reckless missions, digging trenches, collecting dog tags and ghostly whispers in the dark. Home before the leaves fall, they thought.
- 12

Roots of Yggdrasil
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie with Rainbow Billy: The Curse of the Leviathan.
Build settlements, explore the Nine Realms, collect artifacts and upgrade your deck to reach the top of Yggdrasil in this post-Ragnarok roguelike city-builder! Can you survive the end of the world?
- 13

Epic Manager - Create Your Own Adventuring Agency!
Single-player alternative to Rainbow Billy: The Curse of the Leviathan — playable solo, no multiplayer required. Shares Indie and Adventure with Rainbow Billy: The Curse of the Leviathan.
Epic Manager is a unique crossover between Sports Management and classic JRPGs. Experience an addictive “one more turn” mix of tycoon strategy, roguelike elements, roster management, combat and character progression, all rooted in an epic yet light-hearted fantasy setting. Rated ‘E’ for EPIC!