What are some alternatives?
When comparing Game Editor and Unity3D, you can also consider the following products
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
RPGBoss - Cross-platform 2D role playing game maker.
MonoGame - MonoGame is an open source implementation of the Microsoft XNA 4 Framework.
Construct Classic - Construct Classic is a free, DirectX 9 game creator for Windows, designed for 2D games.
Corona SDK - Cross-platform mobile app development.