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

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

Balatro
Shared: Card Game · Roguelike Deckbuilder · Roguelike

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

Dicey Dungeons
Shared: Roguelike Deckbuilder · Card Battler · Roguelike

Wildfrost
Shared: Roguelike Deckbuilder · Card Game · Card Battler

9 Kings
Shared: Roguelike · Card Game · Roguelike Deckbuilder

Monster Train
Shared: Card Game · Card Battler · Deckbuilding

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

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

Yao-Guai Hunter
Shared: Roguelike Deckbuilder · Card Game · Roguelike

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

Griftlands
Shared: Card Battler · Deckbuilding · Card Game

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

Inscryption
Shared: Card Game · Card Battler · Deckbuilding

Black Jacket
Shared: Roguelike Deckbuilder · Card Game · Roguelike

Roguebook
Shared: Card Game · Deckbuilding · Roguelike

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

Guild of Dungeoneering Ultimate Edition
Shared: Roguelike Deckbuilder · Roguelike · Card Game

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

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

Backpack Hero
Shared: Roguelike Deckbuilder · Turn-Based · Deckbuilding

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

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

Blood Card
Shared: Roguelike Deckbuilder · Card Game · Card Battler