I'm actually still working on something similar but, basically, no longer trying to run a business selling educational games (more, profits from commercial development contracts with actual budgets funding the cooler projects).
Good questions. I don't know for sure, but I know a couple of my apps have been delisted because I haven't updated them (they worked just fine and since then I upgraded and lost the development environment used).
I'm actually still working on something similar but, basically, no longer trying to run a business selling educational games (more, profits from commercial development contracts with actual budgets funding the cooler projects).