README.md: mention v3.4.0 availability, add link to Cubic Nightmare

README.md

@@ -4,6 +4,7 @@ jMonkeyEngine
 [![Build Status](https://github.com/jMonkeyEngine/jmonkeyengine/workflows/Build%20jMonkeyEngine/badge.svg)](https://github.com/jMonkeyEngine/jmonkeyengine/actions)
 
 jMonkeyEngine is a 3-D game engine for adventurous Java developers. It’s open-source, cross-platform, and cutting-edge.
+v3.4.0 is the latest stable version of the Engine.
 v3.3.2 is the latest stable version of the jMonkeyEngine SDK.
 
 The engine is used by several commercial game studios and computer-science courses. Here's a taste:
@@ -25,6 +26,7 @@ The engine is used by several commercial game studios and computer-science cours
  - [Leap](https://gamejolt.com/games/leap/313308)
  - [Jumping Jack Flag](http://timealias.bplaced.net/jack/)
  - [PapaSpace Flight Simulation](https://www.papaspace.at/)
+ - [Cubic Nightmare](https://jaredbgreat.itch.io/cubic-nightmare)
 
 ## Getting started