Games like PolyBoost
Games like PolyBoost include Downwell, Super Meat Boy, Celeste, Geometry Dash, and Thomas Was Alone. We matched them by the tags players give PolyBoost on Steam (Precision Platformer, 2D Platformer, Racing, Tutorial, and Arcade): closest matches first, and among equally close ones the better-known games.

Downwell
Shared: Precision Platformer · 2D Platformer · Arcade

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

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

Geometry Dash
Shared: Precision Platformer · 2D · Colorful

Thomas Was Alone
Shared: 2D Platformer · Precision Platformer · 2D

Orbt XL
Shared: Arcade · 2D · Action

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

Twin Shot Deluxe
Shared: 2D Platformer · Action · Arcade

JellyCar Worlds
Shared: 2D Platformer · Precision Platformer · Racing

SANABI
Shared: 2D Platformer · Action · 2D

Retrowave
Shared: Racing · Action · Casual

N++ (NPLUSPLUS)
Shared: Precision Platformer · 2D Platformer · Action

pureya
Shared: Arcade · 2D · Casual

Razortron 2000
Shared: Racing · Casual · Arcade

Drift86
Shared: Racing · Arcade · Casual

A Dance of Fire and Ice
Shared: Arcade · 2D · Colorful

Vampire Survivors
Shared: 2D · Arcade · Casual

Ambidextro
Shared: Precision Platformer · 2D Platformer · Action

PAC-MAN™ Championship Edition DX+
Shared: Arcade · Action · 2D

Timberman
Shared: Casual · Action · 2D

Shelldiver
Shared: Arcade · Casual · 2D

UFO 50
Shared: Action · Arcade · 2D

Super Hexagon
Shared: Arcade · Action · Indie

Super Mombo Quest
Shared: Precision Platformer · Action · Arcade