Games like Crazy 21
Games like Crazy 21 include Plants vs. Zombies GOTY Edition, Balatro, Banana, Bloons TD 6, and Game Dev Tycoon. We matched them by the tags players give Crazy 21 on Steam (Casual, Strategy, Indie, Card Game, and 2D): closest matches first, and among equally close ones the better-known games.

Plants vs. Zombies GOTY Edition
Shared: Strategy · Casual · 2D

Balatro
Shared: Card Game · Strategy · Indie

Banana
Shared: Casual · 2D · Singleplayer

Bloons TD 6
Shared: Strategy · Casual · Singleplayer

Game Dev Tycoon
Shared: Indie · Strategy · Casual

Plague Inc: Evolved
Shared: Strategy · Indie · Casual

911 Operator
Shared: Strategy · Indie · Casual

UNO
Shared: Card Game · Casual · Strategy

Zup! S
Shared: Casual · Indie · 2D

Slay the Spire
Shared: Card Game · Strategy · Indie

Slay the Spire 2
Shared: Card Game · Strategy · Indie

Reus
Shared: Strategy · Indie · Casual

Kingdom Rush - Tower Defense
Shared: Strategy · Casual · 2D

Bloons TD 5
Shared: Strategy · Casual · Family Friendly

100% Orange Juice
Shared: Strategy · Card Game · Casual

Golf With Your Friends
Shared: Casual · Indie · Family Friendly

Mini Motorways
Shared: Strategy · Casual · Indie

Mini Metro
Shared: Strategy · Indie · Casual

Town of Salem
Shared: Strategy · Indie · Casual

Scribblenauts Unlimited
Shared: Casual · 2D · Family Friendly

Circle Empires
Shared: Strategy · Casual · Indie

Golf Peaks
Shared: Strategy · Casual · Card Game

DETOUR
Shared: Strategy · Indie · Casual

Battle Ranch: Pigs vs Plants
Shared: Strategy · Casual · Indie