Games like Across the Obelisk
Games like Across the Obelisk include Slay the Spire, Balatro, Slay the Spire 2, Gordian Quest, and Monster Train. We matched them by the tags players give Across the Obelisk on Steam (Casual, Adventure, Tactical, Turn-Based Strategy, and Roguelike Deckbuilder): 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

Gordian Quest
Shared: Adventure · Card Game · Tactical

Monster Train
Shared: Card Game · Card Battler · Turn-Based Strategy

Dicey Dungeons
Shared: Roguelike Deckbuilder · Deckbuilding · Card Battler

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

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

Overdungeon
Shared: Casual · Roguelike Deckbuilder · Adventure

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

Wildfrost
Shared: Roguelike Deckbuilder · Card Game · Card Battler

Black Jacket
Shared: Roguelike Deckbuilder · Card Game · Roguelike

Backpack Hero
Shared: Roguelike Deckbuilder · Deckbuilding · Roguelike

9 Kings
Shared: Card Game · Roguelike · Roguelike Deckbuilder

LONESTAR
Shared: Roguelike · Roguelike Deckbuilder · Turn-Based Strategy

Chrono Ark
Shared: Roguelike Deckbuilder · Adventure · Card Game

DICEOMANCER
Shared: Card Game · Roguelike Deckbuilder · Card Battler

Monster Train 2
Shared: Roguelike Deckbuilder · Card Game · Turn-Based Strategy

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

Loop Hero
Shared: Tactical · Roguelike · Deckbuilding

Hand of Fate
Shared: Roguelike Deckbuilder · Roguelike · Card Game

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

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

Roguebook
Shared: Card Game · Deckbuilding · Indie