Kush Quest is currently unavailable on the Google Play/ App Stores. In order to play Kush Quest on your Android phone you will need to download the Android Game player App "OHRRPGCE Game". This app was created by the people who made the program I use to create Kush Quest and I take no credit. You can learn more about OHRRPGCE here. You will also need to download the additional file for the game itself titled KushQuest.rpg. The files can be found at the download links below.
Once you have downloaded both files, You will need to give the OHRRPGCE App permission to load the Kush Quest game file. Due to the game being downloaded from a third party site, most phones will automatically block the Game player from loading and accessing files on your phone. You will need to go into the settings section on your phone, then apps and then app permissions. Allow OHRRPGCE app to access files on your phone. The only files it will be accessing is the game file and your game save progress. Once you have everything setup, start you OHRRPGCE App. When the app comes up click the folder labelled O/ (Pictured below)
Then Click the folder labelled Download
Then click Kush Quest... GOOD LUCK!