There's an achievement for the 5th anniversary Fruit Ninja in which you must land a combo after the time runs out in Zen Mode. How do I get this achievement?
In Zen mode, it's quite possible for fruit to still show up even after the timer has expired. Know that you can still swipe on the screen after the timer has expired. If you wait to swipe the last wave of fruit until after the timer expires (and can avoid slicing the Pomegranate that appears right as the timer expires) you can get an easy combo.