Since game design is a business, I decided to see what's really selling well for the PS4.
I did this search a week ago, and at the time, out of the top 20 bestsellers on Amazon 10 had not even been released yet. By now some have been released. But others still have not. And yet others...
It's necessary to collect at least three the same colors balls in the chains to destroy them.
If after two moves in succesion a chain of balls isn't destroyed, all balls will be shifted one row down. And a new top row containing balls of all colors will be added.