Google play music is most downloaded app in the android app store .because most of the phone given this app inbuilt due to this its downloaded number is so high otherwise google play music is not a great app for music espacially in india .lots of features are given in the other western country but in india features like radio and autometically album downloaded is not given in the india .
In term of music player google is decent player but if you like more custamization in your music player then go for other player.