Games like The Abyss Within
Games like The Abyss Within include Slay the Spire, Slay the Spire 2, Balatro, Monster Train, and 9 Kings. We matched them by the tags players give The Abyss Within on Steam (Roguelike Deckbuilder, Card Battler, Card Game, Difficult, and Dungeon Crawler): closest matches first, and among equally close ones the better-known games.

Slay the Spire
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Slay the Spire 2
Shared: Card Game · Roguelike Deckbuilder · Roguelike

Balatro
Shared: Roguelike Deckbuilder · Card Game · Roguelike

Monster Train
Shared: Card Battler · Card Game · Difficult

9 Kings
Shared: Card Game · Roguelike Deckbuilder · Roguelike

Die in the Dungeon
Shared: Roguelike Deckbuilder · Card Game · Card Battler

Wildfrost
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Vampire Crawlers: The Turbo Wildcard from Vampire Survivors
Shared: Card Battler · Dungeon Crawler · Card Game

Dice & Fold
Shared: Card Battler · Roguelike Deckbuilder · Dungeon Crawler

Dicey Dungeons
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Banners of Ruin
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Astrea: Six-Sided Oracles
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Hadean Tactics
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Super Fantasy Kingdom
Shared: Card Game · Roguelike Deckbuilder · Roguelike

Breachway
Shared: Card Game · Roguelike Deckbuilder · Card Battler

Darkest Dungeon®
Shared: Dungeon Crawler · Difficult · Roguelike

He is Coming
Shared: Roguelike · Dungeon Crawler · Card Game

Decktamer
Shared: Roguelike Deckbuilder · Card Game · Card Battler

Library Of Ruina
Shared: Card Game · Difficult · Strategy

Dungeons & Degenerate Gamblers
Shared: Roguelike Deckbuilder · Card Game · Card Battler

Across the Obelisk
Shared: Roguelike Deckbuilder · Card Game · Card Battler

StarVaders
Shared: Roguelike Deckbuilder · Difficult · Card Game

Inscryption
Shared: Card Battler · Card Game · Roguelike

Chrono Ark
Shared: Roguelike Deckbuilder · Card Game · RPG