Godot Engine - Feature-packed 2D and 3D open source game engine.
ENIGMA – LateralGM - LateralGM is a powerful IDE for ENIGMA, and both of these combine to offer you a cross-platform game environment.
Unity - The multiplatform game creation tools for everyone.
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
Adventure Game Studio - Adventure Game Studio provides the tools to make your own adventure, for free!
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.