Games like OPA: Super Janken
Games like OPA: Super Janken include Slay the Spire 2, Slay the Spire, Magic: The Gathering Arena, GWENT: The Witcher Card Game, and Balatro. We matched them by the tags players give OPA: Super Janken on Steam (Strategy, Card Game, Roguelike, Card Battler, and Trading Card Game): closest matches first, and among equally close ones the better-known games.

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

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

Magic: The Gathering Arena
Shared: Strategy · Card Game · Trading Card Game

GWENT: The Witcher Card Game
Shared: Card Game · Strategy · Trading Card Game

Balatro
Shared: Card Game · Roguelike · Strategy

Shadowverse: Worlds Beyond
Shared: Card Battler · Trading Card Game · Strategy

9 Kings
Shared: Strategy · Roguelike · Card Game

Inscryption
Shared: Card Game · Card Battler · Roguelike

Animation Throwdown: The Quest for Cards
Shared: Card Game · Strategy · Card Battler

Slots & Daggers
Shared: Strategy · Roguelike · 1990's

Stacklands
Shared: Card Game · Strategy · Card Battler

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

Rento Fortune: Online Dice Board Game (大富翁)
Shared: Strategy · Card Game · Trading Card Game

DICEOMANCER
Shared: Strategy · Card Game · Card Battler

Die in the Dungeon
Shared: Strategy · Roguelike · Card Game

Gremlins, Inc.
Shared: Card Game · Strategy · Tabletop

Monster Train
Shared: Card Game · Card Battler · Roguelike

Tabletop Simulator
Shared: Card Game · Tabletop · Trading Card Game

Dungeons & Degenerate Gamblers
Shared: Strategy · Roguelike · Card Game

Backpack Battles
Shared: Strategy · Roguelike · Multiplayer

Armello
Shared: Card Game · Strategy · Hand-drawn

Griftlands
Shared: Card Battler · Card Game · Strategy

Yu-Gi-Oh! Legacy of the Duelist
Shared: Card Game · Card Battler · Strategy

Super Fantasy Kingdom
Shared: Strategy · Roguelike · Card Game