Not everyone who might be interested in your game wants the APK version and all I see is 1 PC specific version listed as 0.1 Old.  I could try your game by using an emulator but why would I want to waste time when there are 3 billion other games that don't require an emulator in addition to the game?  

I was literally about to download the free version to see if it was worth $8 and I see there is only the first version for PC, if you want full market share make a version for each of those markets (Mobile, PC and Mac).