Games like Quantum Project
Games like Quantum Project include SANABI, Ori and the Will of the Wisps, Skul: The Hero Slayer, Katana ZERO, and Celeste. We matched them by the tags players give Quantum Project on Steam (Action, Adventure, Platformer, Action-Adventure, and 2D Platformer): closest matches first, and among equally close ones the better-known games.

SANABI
Shared: Action · Adventure · 2D Platformer

Ori and the Will of the Wisps
Shared: Platformer · Action · Adventure

Skul: The Hero Slayer
Shared: Action · Platformer · Pixel Graphics

Katana ZERO
Shared: Action · Platformer · Pixel Graphics

Celeste
Shared: Platformer · 2D Platformer · Pixel Graphics

Warhammer 40,000: Space Marine 2
Shared: Action · Adventure · Action-Adventure

Anomaly Agent
Shared: 2D Platformer · Platformer · Side Scroller

Broforce
Shared: Action · Platformer · Pixel Graphics

Axiom Verge 2
Shared: Action · Adventure · Platformer

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

Shiro
Shared: Action · Adventure · Platformer

Owlboy
Shared: Adventure · Platformer · Pixel Graphics

BlazBlue Entropy Effect
Shared: Action · Action-Adventure · Platformer

Tomb Raider Game of the Year
Shared: Action · Adventure · Action-Adventure

Sonic Superstars
Shared: Action · Platformer · Adventure

Deadlight
Shared: Action · Platformer · Adventure

Shovel Knight: Treasure Trove
Shared: Platformer · Adventure · Action

F.I.S.T.: Forged In Shadow Torch
Shared: Action · Platformer · Adventure

Prince of Persia The Lost Crown
Shared: Action · 2D Platformer · Adventure

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

Well Dweller
Shared: Action · Action-Adventure · Adventure

MO:Astray
Shared: Action · Adventure · Platformer

Sonic Origins
Shared: Action · Adventure · 2D Platformer

Mina the Hollower
Shared: Action-Adventure · Platformer · 2D Platformer