Games like Squirreltopia
Games like Squirreltopia include Celeste, Super Meat Boy, SANABI, VVVVVV, and Jump King. We matched them by the tags players give Squirreltopia on Steam (2D Platformer, Precision Platformer, Pixel Graphics, Retro, and Souls-like): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Precision Platformer · Pixel Graphics · 2D Platformer

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

SANABI
Shared: Pixel Graphics · 2D Platformer · Action

VVVVVV
Shared: Precision Platformer · Pixel Graphics · 2D Platformer

Jump King
Shared: Precision Platformer · Pixel Graphics · Difficult

Downwell
Shared: Precision Platformer · Pixel Graphics · 2D Platformer

Hollow Knight
Shared: Souls-like · Difficult · 2D

Momodora: Reverie Under The Moonlight
Shared: 2D Platformer · Pixel Graphics · Souls-like

Shovel Knight: Treasure Trove
Shared: Pixel Graphics · Retro · 2D

Katana ZERO
Shared: Pixel Graphics · 2D Platformer · Action

Pizza Tower
Shared: 2D Platformer · Pixel Graphics · Indie

The Messenger
Shared: Retro · Pixel Graphics · 2D Platformer

Titan Souls
Shared: Pixel Graphics · Souls-like · Difficult

Blasphemous
Shared: Pixel Graphics · Souls-like · 2D

Geometry Dash
Shared: Precision Platformer · Difficult · 2D

Blasphemous 2
Shared: 2D Platformer · Difficult · Pixel Graphics

Ambidextro
Shared: Precision Platformer · 2D Platformer · Pixel Graphics

Rain World
Shared: Pixel Graphics · Difficult · Indie

Gravity Circuit
Shared: Pixel Graphics · 2D Platformer · 2D

Skul: The Hero Slayer
Shared: Pixel Graphics · Indie · 2D

UFO 50
Shared: Pixel Graphics · Retro · Indie

Sonic Origins
Shared: 2D Platformer · Retro · Pixel Graphics

NINJA GAIDEN: Ragebound
Shared: 2D Platformer · Pixel Graphics · Retro

Gato Roboto
Shared: Pixel Graphics · Indie · 2D