Marketing an Android Game in SA

Hi guys.

I wrote an Android game called Farm Wars and now I need to start doing marketing for it to get players. Currently it gets about 10-15 new installs per day from the Play Store (organic) which is really really slow, especially if you take into consideration that only a small amount of players actually sticks around and keep playing.

Does anyone here have some tips for me perhaps how to market an Android game in South Africa without blowing thousands in advertising? (Very tight budget as I have quit my job a year ago to just write this game).

All suggestions would be much appreciated. Happy to give you free in-game currency in exchange for good advice... ;)
Link to the game: https://play.google.com/store/apps/details?id=za.co.inventit.farmwars

Thank you!