Thought I would chime in on this one 
Some things to understand about Google Play.
While it is true that your app is published and available within 1-3 hours in reality (in my experience) it takes between 1-2 weeks for it to start moving and searchable (unless for some reason it is popular right out the gate). There are some exceptions to this rule (a) is it free, paid etc. ( B) is it getting a fair amount of downloads, and © do you have a lot of inbound links pointed to your app on Google Play (Websites, Reviews, Is it popular in other stores etc.).
Over the past year (year and a half) Google Play has become a free-for-all ecosystem and has been flooded with so many games (40% of them being fake) that it is becoming harder and harder to navigate.
Keep in mind is that the Play Store Search also works like Google Search first and foremost based on relevance so a search on Google Play for one of my new puzzle games The Billy Blob Saga you will find me at number 27 HOWEVER if search for “The Billy Blob Saga” with quotes it will show up number one. The reason for this is the games that show before me are either advertising (install exchange) or in some cases have very spammmmmy descriptions which will mess with Googles indexing until such time they are pulled by the automated engine at which time they simply change the product id and re-upload it and start the process all over again.
The same is true for your game, if you are asking people to download it just by putting in the name have them put quotes around your name like “Music History Flashcards” and it will be the only result they see until such time your app becomes more relevant to the Google Skynet System.
I posted on the pitfalls of each store a few weeks ago on my linked in and you can read it here if you like https://www.linkedin.com/today/post/article/20140711160710-146086161-google-play-amazon-app-store-microsoft-store-and-itunes?trk=prof-post
Anymore, I only use Google Play for testing features, fine tuning and fixing bugs before pushing to other stores like Apple.
If I were wanting to make my games anything more than a hobby or my own personal amusement, I wouldn’t even bother with Google I would be exclusive to Apple until such time Google was able to sober up their Skynet system because at the moment it is to drunk with power.
Just my two cents.
Also: I would play with your price range, 99 cents will show up in more “related/similar” results than $6.43 will and I think you will find you will get more downloads at 99 cents than you ever will at the current price.
You can get away with a price like that on Apple but unless you are offering something they can’t live without Google users will not pay that much for a app/game.