I released a geography quiz game last week which uses Xamarin but not MonoGame, it's called Geo Wiz if anyone is curious.
I've emailed all of the review sites in the list but no joy yet. I did however find a website called androidapppromotion.com where you install an app that functions as a developer community, so you all download each others apps to bump the figures up.
It's free and seems to work quite well. I got about 30 downloads in the hour I played around with it, so definitely worth a look.