Games like Number 21 - Death Deal
Games like Number 21 - Death Deal include Inscryption, Buckshot Roulette, Mini Motorways, Mini Metro, and Slay the Spire. We matched them by the tags players give Number 21 - Death Deal on Steam (Strategy, Indie, Simulation, Puzzle, and Card Game): closest matches first, and among equally close ones the better-known games.

Inscryption
Shared: Card Game · Horror · Puzzle

Buckshot Roulette
Shared: Strategy · Horror · Indie

Mini Motorways
Shared: Strategy · Simulation · Indie

Mini Metro
Shared: Strategy · Puzzle · Simulation

Slay the Spire
Shared: Card Game · Strategy · Turn-Based

Plague Inc: Evolved
Shared: Strategy · Simulation · Indie

Papers, Please
Shared: Indie · Simulation · Puzzle

Bendy and the Ink Machine
Shared: Horror · Puzzle · Indie

Balatro
Shared: Card Game · Strategy · Indie

Welcome to the Game II
Shared: Strategy · Indie · Horror

Poppy Playtime
Shared: Horror · Puzzle · Indie

Into the Breach
Shared: Strategy · Indie · Puzzle

Simmiland
Shared: Indie · Simulation · Strategy

LIMBO
Shared: Indie · Puzzle · Dark

Democracy 3
Shared: Strategy · Simulation · Indie

Game Dev Tycoon
Shared: Indie · Simulation · Strategy

Sally Face - Episode One
Shared: Indie · Puzzle · Horror

Just Go
Shared: Strategy · Simulation · Card Game

The Legend of Bum-Bo
Shared: Indie · Strategy · Puzzle

Little Nightmares
Shared: Horror · Indie · Puzzle

BidKing
Shared: Strategy · Simulation · Puzzle

Totally Accurate Battle Simulator
Shared: Simulation · Strategy · Indie

Welcome to the Game
Shared: Simulation · Indie · Horror

Reus
Shared: Strategy · Indie · Simulation