Lemur is my UI toolkit. Zay-ES is my open source entity system. Forum search is your friend there. Or just go to the simsilica site.
It’s all 2D. The star field is multiple layers that move at different rates.
I mean, in the end it’s personal preference, but I find that approach too far disconnects the problem from the answer. I tired to design it so it could even work with a touch screen as I may try porting it to Android someday.
Mythruna is my commercial project. http://mythruna.com/ It just hasn’t gotten much love lately.
I may swing back and cleanup Math Attack to open source it. I don’t really have time to make it presentable right now, though most of the code is pretty clean.
Edit: actually I’ll save you some other clicking: http://www.simsilica.com/open-source-tools/