I stumbled across this yesterday.
I don't know that I'll try to fill in every block, but there are a fair number I'm planning on doing anyway... Plus it's fun to challenge yourself.
I've been steadily working on some of my minis, mostly the wizard and apprentice for the new Frostgrave campaign starting this weekend.
Doctors Ecclescake (wizard) and Payne (apprentice), from Heresy minis.
Trying to give their bases a cobblestone/fieldstone sort of look. I've not done a whole lot with greenstuff, so every time I mix some of it up, it's a learning experience. In this case I learned that trying to sculpt around a mini is hard. Worse when the mini is already painted...