Godot is an advanced, feature-packed, multi-platform 2D and 3D open source game engine.
Extremely flexible and light, can run on multiple platform and export in several formats and platforms too ( Windows, Linux, Mac, but also HTML5 and Android). Can be used to develop 2D or 3D Games and applications, with a really clean and uncluttered Visual Editor. Fully scriptable, can handle physics, lighting, shading and more.

Credits: godotengine.org

For a complete list of features, visit the Godot website, or the Godot Documentation