Games like Starless Abyss
Games like Starless Abyss include Balatro, Slay the Spire 2, Slay the Spire, Darkest Dungeon®, and FTL: Faster Than Light. We matched them by the tags players give Starless Abyss on Steam (Strategy, Indie, Lovecraftian, Roguelike Deckbuilder, and Turn-Based Combat): closest matches first, and among equally close ones the better-known games.

Balatro
Shared: Roguelike Deckbuilder · Strategy · Indie

Slay the Spire 2
Shared: Strategy · Roguelike Deckbuilder · Indie

Slay the Spire
Shared: Roguelike Deckbuilder · Strategy · Indie

Darkest Dungeon®
Shared: Turn-Based Combat · Lovecraftian · Strategy

FTL: Faster Than Light
Shared: Strategy · Indie · Space

9 Kings
Shared: Strategy · Roguelike Deckbuilder · Turn-Based Combat

Die in the Dungeon
Shared: Strategy · Roguelike Deckbuilder · Indie

The Last Spell
Shared: Strategy · Turn-Based Combat · Singleplayer

Into the Breach
Shared: Strategy · Indie · Turn-Based Strategy

Library Of Ruina
Shared: Strategy · Turn-Based Combat · Indie

Roguebook
Shared: Indie · Strategy · Singleplayer

Shogun Showdown
Shared: Strategy · Roguelike Deckbuilder · Turn-Based Combat

RACCOIN: Coin Pusher Roguelike
Shared: Strategy · Roguelike Deckbuilder · Singleplayer

Quasimorph
Shared: Strategy · Turn-Based Combat · Singleplayer

Darkest Dungeon® II
Shared: Lovecraftian · Singleplayer · Turn-Based Combat

Stoneshard
Shared: Strategy · Roguelike · 2D

Super Fantasy Kingdom
Shared: Strategy · Roguelike Deckbuilder · Roguelike

Cobalt Core
Shared: Strategy · Roguelike Deckbuilder · Roguelike

Chrono Ark
Shared: Strategy · Roguelike Deckbuilder · Indie

Dungeons & Degenerate Gamblers
Shared: Strategy · Roguelike Deckbuilder · Roguelike

Backpack Hero
Shared: Roguelike Deckbuilder · Strategy · 2D

Dicey Dungeons
Shared: Roguelike Deckbuilder · Indie · Strategy

LONESTAR
Shared: Strategy · Roguelike Deckbuilder · Turn-Based Combat

Cosmoteer: Starship Architect & Commander
Shared: Indie · Strategy · Singleplayer