Worddata has lots of great articles about ASO. There are tools out there that show you if your chosen keywords are highly competitive and should be replaced with less popular keywords so you have a chance at showing in search results.
Possibly because your title contains popular keywords so your game is still in a large list. Balls Falls or Balls Blitz might do better. From what I've read so far about ASO I think it's all about individual keywords not phrases.
Worddata has lots of great articles about ASO. There are tools out there that show you if your chosen keywords are highly competitive and should be replaced with less popular keywords so you have a chance at showing in search results.