Though I did want to expand on the original at least a little, this project was a way to learn Unity for me.
But it ended up taking me much longer than intended, and I wasn't happy with how some of it was turning out. I was determined to complete it to some degree at least so I shelved other stuff I wanted to add and just finished off the existing features.
There's a good chance I'll be slowly adding more stuff in depending on what's possible.