I love candy crush, that's my only game. I play at night and whenever I get push notifications of life being full or even just 1 life generated.
When I'm busy all day at the end of the day I check all my notifications and I end up playing candy crush for an hour or something.
So I think push notification is a feature we should add for player retention and active gameplay.
Another feature is for the loading page before the game. Candy Crush puts short messages that describes their USPs See attached photo.
Messages like
  • swipe the stress away
  • swipe match relax
  • story behind the game
  • FAQs or Trivias