Games like Proyecto Flamingo X1
Games like Proyecto Flamingo X1 include Hollow Knight, Hollow Knight: Silksong, Skul: The Hero Slayer, Geometry Dash, and Spelunky. We matched them by the tags players give Proyecto Flamingo X1 on Steam (Action, Indie, Simulation, 2D, and Difficult): closest matches first, and among equally close ones the better-known games.

Hollow Knight
Shared: Difficult · Indie · Platformer

Hollow Knight: Silksong
Shared: Indie · Difficult · 2D

Skul: The Hero Slayer
Shared: Action · Indie · 2D

Geometry Dash
Shared: Difficult · 2D · Singleplayer

Spelunky
Shared: Indie · Platformer · Difficult

Game Dev Tycoon
Shared: Indie · Simulation · Singleplayer

The Binding of Isaac
Shared: Indie · Action · Difficult

The Binding of Isaac: Rebirth
Shared: Indie · Difficult · Replay Value

Super Meat Boy
Shared: Indie · Difficult · Platformer

Cuphead
Shared: Difficult · 2D · Platformer

Papers, Please
Shared: Indie · Simulation · Singleplayer

Plague Inc: Evolved
Shared: Simulation · Indie · Singleplayer

Celeste
Shared: Indie · Difficult · Platformer

Nine Sols
Shared: Action · 2D · Difficult

The Escapists
Shared: 2D · Simulation · Indie

Angvik
Shared: Indie · Action · 2D

Rogue Legacy
Shared: Indie · Action · Platformer

Super Hexagon
Shared: Indie · Difficult · Action

Mark of the Ninja
Shared: Indie · Action · 2D

Katana ZERO
Shared: Action · Indie · Platformer

LIMBO
Shared: Indie · 2D · Platformer

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

SANABI
Shared: Action · Indie · 2D

Rogue Legacy 2
Shared: Action · Indie · Platformer