Godot Engine - Feature-packed 2D and 3D open source game engine.
Granny Smith - Granny Smith is an Addictive, Action, Puzzle-Platform, Side-Scroll, and Single-player video game developed and published by Medicore.
Cyberix3D - Free online 3D Game Maker. Make your own 3D games online!
Megatroid - Megatroid is a gorgeous, Action-Adventure, Puzzle-platform, Side-scroll, Sci-fi, and Single-player video game developed and published by Triolith Entertainment AB.
Unity - The multiplatform game creation tools for everyone.
N++ - N++ is a Puzzle-Platform and Single-player video game that takes place in the 2D world, developed by Metanet Software, Inc.