In case someone missed them, here are the game engines at your disposal for the B4x products:
B4a: libGDX
B4j: SimpleGameEngine + jBox2D
B4i: iSpriteKit
Generally speaking, an engine is considered to "do more" or have more tools and related support than a framework, which is itself is often just a loose collection of related functionality exposed through some unified API.
I am using Babylon.js which can be used in B4X via HTML5 It's a great 3D engine. Game coming soon - well an Alpha / early Beta test version at the very least.