Armory is getting more and more attention. This series of tutorials by Serapth will help you get started!
Armory is a newly free for all open source game engine built to run inside of Blender (2.7 and 2.8), while being programmed using either logic nodes or the Haxe programming language.
This tutorial series covers all aspects of working with the Armory game engine in both text and video formats. New topics are being covered daily.