Godot Engine - Feature-packed 2D and 3D open source game engine.
Blitz3D - Create 2D and 3D Games for Windows.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
BlitzPlus - Create 2D Games for Windows.
BYOND - BYOND is the premier community for making and playing online multiplayer games.
Monkey 2 - An easy to use, cross platform, games oriented programming language