I suppose an obvious idea for a bonus stage would be some kind of "fruit frenzy". Perhaps have a chain/vine level of some sort (probably similar to the original chain screen) populated with snapjaws, and have fruit appear in random places for a short period of time with the goal of scoring how many fruit you can hit. Or, maybe have a total of ten fruit possible to hit, with an increased bonus for each consecutive fruit not missed. Like 100, 100, 300, 300, 400, 400, 800, 800, 1200, 1600.