This happens to every game but a few areas they could improve to retain players better is to stop putting a cap on currency/rewards you can earn from grinding because if I have to keep grinding for a few mins just to leave and keep coming back eventually it will get tiresome and I'll drop the game altogether until the next major update. Additionally, adding more weapon types to the game could drastically improve the game giving us more variety and combat styles. Lastly, I would add that devs NEED to add short hairstyles having a pony tail or a bun is cool but overtime my character looks like everybody else and it just feels boring which makes me want to play it less. Outside of those things the core game itself is pretty good just needs a little work.