I'm so almost done. Most of the bugs are gone.
Except there's one thing that I just can't seem to resolve. There's some weird gotcha in libgdx's audio engine (on Android) where there will be a brief pause, or drop in framerate, whenever a sound effect stops playing. During most of the game, there's very few sounds, so it's not a huge issue, but the lasers that the blue guards shoot (and that Robo-Ninja shoots) are causing problems.
I've tried all sorts of things, but I just can't seem to work around it.
I've got a couple more things to try, and if those don't work, then I'm giving up and removing the laser sounds. Ugh.