Games like SmartSoules
Games like SmartSoules include Celeste, LIMBO, SANABI, Thomas Was Alone, and Super Meat Boy. We matched them by the tags players give SmartSoules on Steam (Adventure, Platformer, 2D Platformer, Side Scroller, and Puzzle Platformer): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Precision Platformer · Platformer · 2D Platformer

LIMBO
Shared: Platformer · Puzzle Platformer · Adventure

SANABI
Shared: Adventure · 2D Platformer · Pixel Graphics

Thomas Was Alone
Shared: Platformer · Side Scroller · 2D Platformer

Super Meat Boy
Shared: Platformer · Precision Platformer · 2D Platformer

VVVVVV
Shared: Platformer · 2D Platformer · Precision Platformer

Pizza Tower
Shared: 2D Platformer · Platformer · Cartoony

Webbed
Shared: 2D Platformer · Puzzle Platformer · Platformer

Owlboy
Shared: Adventure · Platformer · Pixel Graphics

Hollow Knight
Shared: Platformer · 2D · Adventure

Jump King
Shared: Adventure · Precision Platformer · Platformer

Rain World
Shared: Platformer · Adventure · 2D

Neva
Shared: Adventure · Platformer · 2D Platformer

Planet of Lana
Shared: Puzzle Platformer · 2D Platformer · Platformer

Shovel Knight: Treasure Trove
Shared: Platformer · Adventure · 2D

Braid
Shared: 2D Platformer · Puzzle Platformer · Platformer

INSIDE
Shared: Puzzle Platformer · Adventure · Atmospheric

MO:Astray
Shared: Adventure · Platformer · Puzzle Platformer

Songs for a Hero - Definitive Edition
Shared: Adventure · 2D Platformer · Platformer

Downwell
Shared: Platformer · Precision Platformer · 2D Platformer

Vibrant Venture
Shared: Adventure · Platformer · 2D Platformer

GRIS
Shared: Adventure · Platformer · Atmospheric

FEZ
Shared: Platformer · Adventure · Pixel Graphics

ANIMAL WELL
Shared: Platformer · Puzzle Platformer · Adventure