Games like Sleepy Heroes
Games like Sleepy Heroes include Slay the Spire 2, Slay the Spire, Inscryption, Balatro, and Monster Train. We matched them by the tags players give Sleepy Heroes on Steam (Card Game, Card Battler, Roguelike, Strategy, and Turn-Based Tactics): 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 · Card Battler · Roguelike

Inscryption
Shared: Card Game · Card Battler · Roguelike

Balatro
Shared: Card Game · Roguelike · Strategy

Monster Train
Shared: Card Battler · Card Game · Roguelike

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

9 Kings
Shared: Strategy · Card Game · Roguelike

Dice & Fold
Shared: Card Battler · Roguelike · Dungeon Crawler

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

Super Fantasy Kingdom
Shared: Strategy · Roguelike · Card Game

He is Coming
Shared: Roguelike · Strategy · Card Game

Wildfrost
Shared: Card Battler · Card Game · Turn-Based Tactics

The Bazaar
Shared: Strategy · Card Battler · Card Game

Infinity Wars: Animated Trading Card Game
Shared: Card Game · Strategy · Card Battler

LONESTAR
Shared: Roguelike · Card Battler · Strategy

Dream of Corpse Lady
Shared: Card Game · Card Battler · Strategy

Into the Breach
Shared: Strategy · Turn-Based Tactics · Roguelike

GWENT: Rogue Mage (Single-Player Expansion)
Shared: Card Game · Strategy · Roguelike

Black Book
Shared: Card Battler · Card Game · Turn-Based Tactics

Yu-Gi-Oh! Master Duel
Shared: Card Game · Strategy · Card Battler

Hadean Tactics
Shared: Card Battler · Card Game · Roguelike

As We Descend
Shared: Card Battler · Card Game · Roguelike

Trials of Fire
Shared: Card Battler · Turn-Based Tactics · Dungeon Crawler

DICEOMANCER
Shared: Card Game · Card Battler · Strategy