Goal: collect all orders and reach 10,000 points to complete the level.
Tips: here you need to collect 15 yellow candies from lucky candies. The focus really is the candy collection and can be passed without having to process keys. Note of where the lucky candy dispensers are and keep matching them and collecting the subsequent yellow candies while keeping the very short-timed bombs in check. Make special candies and combos so there can be multiple lucky and yellow candies processed at the same time. See how this level is done in video below. Good luck.
Candy Crush Saga Level 2520 walkthrough video