Games like Smack Monkey
Games like Smack Monkey include Celeste, Jump King, Pizza Tower, Super Meat Boy, and Human Fall Flat. We matched them by the tags players give Smack Monkey on Steam (Precision Platformer, Parkour, Pixel Graphics, Funny, and Nature): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Precision Platformer · Pixel Graphics · Platformer

Jump King
Shared: Precision Platformer · Pixel Graphics · Adventure

Pizza Tower
Shared: Funny · Pixel Graphics · Cartoony

Super Meat Boy
Shared: Precision Platformer · Pixel Graphics · Platformer

Human Fall Flat
Shared: Funny · Adventure · Puzzle Platformer

I wanna be the Creator
Shared: Precision Platformer · Adventure · Platformer

Pogostuck: Rage With Your Friends
Shared: Precision Platformer · Adventure · Funny

Webbed
Shared: Pixel Graphics · Puzzle Platformer · Cute

Dungeon Munchies
Shared: Pixel Graphics · Funny · Adventure

The End Is Nigh
Shared: Precision Platformer · Platformer · Adventure

White Knuckle
Shared: Parkour · Precision Platformer · Pixel Graphics

A Difficult Game About Climbing
Shared: Precision Platformer · Adventure · Funny

Outcore: Desktop Adventure
Shared: Adventure · Psychological Horror · Pixel Graphics

There Is No Game: Wrong Dimension
Shared: Pixel Graphics · Funny · Adventure

Gorilla Tag
Shared: Parkour · Funny · Psychological Horror

Shovel Knight: Treasure Trove
Shared: Pixel Graphics · Platformer · Adventure

Broforce
Shared: Pixel Graphics · Platformer · Action

Undertale
Shared: Pixel Graphics · Funny · Comedy

VVVVVV
Shared: Precision Platformer · Pixel Graphics · Platformer

MO:Astray
Shared: Pixel Graphics · Adventure · Platformer

Squishy the Suicidal Pig
Shared: Pixel Graphics · Platformer · Adventure

Portal 2
Shared: Platformer · Funny · Puzzle Platformer

Owlboy
Shared: Pixel Graphics · Adventure · Platformer

Reventure
Shared: Pixel Graphics · Adventure · Platformer