The update that I’ve been planning on is finally released. I can now create custom movement paths for the entities so that they don’t just go in the default space invaders movement. I’ve implemented a level-type which I call “Insanity” for everyone to play in the latest version of the jar in the OP.
I’ll be working on a few new level-types over the next few days and hopefully I’ll get them implemented and working.
Edit:
Also, thanks to the new custom movement for the aliens, I can add in larger sprites, boss battles, etc…