Hello fellow android user! Even though I am a bit late, I'm here to help with joiplay and the game. (if you didn't fix it yet)
First of all you can't download joiplay from the appstore, so you will have to download it from the internet. (Possibly because it is an unapproved emulator or something, which I don't really know)
Once you get joiplay, you should unzip the game, if you somehow managed to run it zipped (you can find downloaded stuff in "My files" application).
Then you just click add game (hidden below +) in joiplay, navigate to the unzipped game folder and choose the .html file. The current version of the game has no problem with saving on joiplay and images also work.