Yes! Bubble Cash is a legitimate cash game app that pays members via PayPal. You can read review after review from players (in the app store) who have earned real cash for playing this game.
In each level, Bub and Bob must defeat each enemy present by trapping them in bubbles and popping, who turn into bonus items when they hit the ground. There are 100 levels total, each becoming progressively more difficult. Bubble Bobble was designed by Fukio "MTJ" Mitsuji.