Games like Cthulhu Dungeon
Games like Cthulhu Dungeon include Balatro, Slay the Spire, Slay the Spire 2, Inscryption, and Vampire Crawlers: The Turbo Wildcard from Vampire Survivors. We matched them by the tags players give Cthulhu Dungeon on Steam (Roguelike Deckbuilder, Card Battler, Card Game, Deckbuilding, and 2D): closest matches first, and among equally close ones the better-known games.

Balatro
Shared: Roguelike Deckbuilder · Card Game · Deckbuilding

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

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

Inscryption
Shared: Card Battler · Card Game · Deckbuilding

Vampire Crawlers: The Turbo Wildcard from Vampire Survivors
Shared: Card Battler · Deckbuilding · Roguelike

Monster Train
Shared: Card Battler · Card Game · Deckbuilding

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

Wildfrost
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Dicey Dungeons
Shared: Roguelike Deckbuilder · Card Battler · Deckbuilding

9 Kings
Shared: Card Game · Roguelike Deckbuilder · Deckbuilding

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

DICEOMANCER
Shared: Card Battler · Card Game · Roguelike Deckbuilder

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

Monster Train 2
Shared: Roguelike Deckbuilder · Card Game · Deckbuilding

Menace from the Deep
Shared: Roguelike Deckbuilder · Deckbuilding · Card Battler

Ratropolis
Shared: Card Battler · Deckbuilding · 2D

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

RACCOIN: Coin Pusher Roguelike
Shared: Roguelike Deckbuilder · Deckbuilding · Roguelike

As We Descend
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Touhou: Lost Branch of Legend
Shared: Roguelike Deckbuilder · Card Battler · Card Game

Vault of the Void
Shared: Roguelike Deckbuilder · Deckbuilding · Card Battler

My Card Is Better Than Your Card!
Shared: Card Game · Deckbuilding · Roguelike Deckbuilder

StarVaders
Shared: Roguelike Deckbuilder · Deckbuilding · Card Game

Breachway
Shared: Card Game · Roguelike Deckbuilder · Deckbuilding