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

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

Balatro
Shared: Card Game · Roguelike Deckbuilder · Deckbuilding

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

Dicey Dungeons
Shared: Roguelike Deckbuilder · Card Battler · Deckbuilding

Wildfrost
Shared: Roguelike Deckbuilder · Card Battler · Card Game

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

9 Kings
Shared: Card Game · Roguelike Deckbuilder · Deckbuilding

Monster Train
Shared: Card Battler · Card Game · Deckbuilding

Inscryption
Shared: Card Game · Card Battler · Deckbuilding

Griftlands
Shared: Card Battler · Deckbuilding · Card Game

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

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

Ratropolis
Shared: Card Battler · Deckbuilding · Card Game

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

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

Black Jacket
Shared: Roguelike Deckbuilder · Card Game · Deckbuilding

DICEOMANCER
Shared: Card Game · Roguelike Deckbuilder · Card Battler

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

Super Fantasy Kingdom
Shared: Card Game · Roguelike · Strategy

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

Combolands: Roguelike Citybuilder
Shared: Roguelike Deckbuilder · Strategy · Roguelike

Roguebook
Shared: Card Game · Deckbuilding · Roguelite

Tower Tactics: Liberation
Shared: Roguelike Deckbuilder · Card Game · Card Battler

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