Games like Monster X Monster
Games like Monster X Monster include Slay the Spire, Slay the Spire 2, Balatro, Dicey Dungeons, and 9 Kings. We matched them by the tags players give Monster X Monster on Steam (Roguelike Deckbuilder, Card Battler, Indie, Deckbuilding, and Roguelite): closest matches first, and among equally close ones the better-known games.

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

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

Balatro
Shared: Roguelike Deckbuilder · Deckbuilding · Roguelike

Dicey Dungeons
Shared: Roguelike Deckbuilder · Card Battler · Deckbuilding

9 Kings
Shared: Roguelike Deckbuilder · Deckbuilding · Roguelike

Inscryption
Shared: Card Battler · Deckbuilding · Card Game

Monster Train
Shared: Card Battler · Roguelite · Deckbuilding

Chrono Ark
Shared: Roguelike Deckbuilder · Indie · RPG

Vault of the Void
Shared: Roguelike Deckbuilder · Indie · Deckbuilding

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

Griftlands
Shared: Card Battler · Deckbuilding · Roguelite

Overdungeon
Shared: Roguelike Deckbuilder · Indie · Card Battler

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

Super Fantasy Kingdom
Shared: Roguelike · Roguelite · RPG

Wildfrost
Shared: Roguelike Deckbuilder · Card Battler · Roguelite

Roguebook
Shared: Indie · Deckbuilding · RPG

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

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

Fate Hunters
Shared: Roguelike Deckbuilder · Card Battler · Indie

DICEOMANCER
Shared: Card Battler · Roguelike Deckbuilder · Deckbuilding

Hand of Fate
Shared: Roguelike Deckbuilder · Deckbuilding · Roguelike

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

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

Gordian Quest
Shared: Card Battler · RPG · Card Game