Again, thanks to all who replied. We are hacking our way through the Pygame jungle...
PygameZero is intriguing. However, we are still not comfortable with making classes (Sprite or Actor). I realize it's "easier", but it's easier for me, not for an average 9th grade student. We will continue hacking away because we believe that BlitzBasic, even though it delivers a very good intro to text coding, is no longer supported and so doesn't offer a good path forward.
I do appreciate the many offers of assistance, code samples, suggestions.... Perhaps after the end of our marking period, I'll post a couple code samples from our students, and that will give everyone an idea of where we are and where we're headed....