Unity - The multiplatform game creation tools for everyone.
Lumix Engine - Open source 3D game designer and engine written in C++.
Pygame - Pygame is a set of Python modules designed for writing games.
Grit Game Engine - The Grit Game Engine is an MIT-Licensed Open Source Game Engine that is highly scriptable via Lua.
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
MOS - Lightweight game engine.