App has a button 'Download from Google Play' that takes you to a page in Google Play where Super Mario Run will be available if they use same package name as in the App Store. Until it becomes available you will get 'Item not found.' in Google Play for that page.
You can also select in the app that we notify you when Super Mario Run becomes available on Google Play.
Page for Super Mario Run is already available in the App Store and you will be able to download it on iOS devices on December 15, 2016. Release date for Android is still unknown.