Its the same kind of challenge as many of the levels. First figure out where your biggest mega bonus's are so you can rack the time up. then notice, by checking under your menu if you have an android which is what I use, that if you keep playing AND don't stop the game it requires less and less bebs, to so the startegy is find the mega bonus early enough to rack the timer over and over in the games, dont stop or quit the games as you fail them so the requirements go down and then out of the blue it will say you have won the game. Here is a hint though. if you do have to start over, lose the first 15-20 games badly as the developer has taught the game to recognize when your getting better and it will stop lowering the required number of bebs sooner. You can look and practice this by watching under the menu.
Good luck.