RPG Maker
Godot Engine
GDevelop
Unreal Engine
Unity
Stencyl
Adventure Game Studio
Orx
BlitzMax
Blitz3D
Monkey 2
Phaser
Cocos2d-x
AppGameKit
Haxe
JMonkeyEngine
RPG Maker
BlitzMaxGodot Engine - Feature-packed 2D and 3D open source game engine.
Blitz3D - Create 2D and 3D Games for Windows.
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
Monkey 2 - An easy to use, cross platform, games oriented programming language
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
Phaser - Desktop and Mobile HTML5 game framework. A fast, free and fun open source framework for Canvas and WebGL powered browser games.