A bit OOT, LibGDX is another game engine, but for the JVM (can use Java, Scala, Clojure, Kotlin, etc), that runs natively on desktop, Android, Web (transpiled to JS), iOS (using RoboVM). It has Lua support as well through 3rd party.
Udacity has Nanodegree using it: https://www.udacity.com/course/mobile-2d-game-developer-nano...
Disclaimer: I'm writing a game using LibGDX.