Pixel: ru² - Pixel: ru² is a 2D, Physics-based Puzzle-Platform, Shooter and Single-player video game by C63 Industries.
Godot Engine - Feature-packed 2D and 3D open source game engine.
Mini Ninjas - Mini Ninjas is an Action-Adventure, Puzzle-Platform and Single-player video game developed by IO Interactive and published by Eidos Interactive.
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
Why So Evil 2: Dystopia - Why So Evil 2: Dystopia is an Adventure-based, Puzzle-Platform, Physics-based and Single-player video game developed by Zonitron Production.
Unity - The multiplatform game creation tools for everyone.