This level is currently nearly impossible to beat without boosters (or even with boosters). This is likely caused by a level buff, lack of moves, an objective which requires insane luck to fulfill, a level glitch, or a design error. This level is currently, or likely one of the hardest levels of the game.
Level 420 is the tenth level in Soda Swamp and the 52nd mixed mode level (45th jelly-order). To pass this level, you must clear 72 double jelly squares and collect 8 jelly fish in 18 moves or fewer.
When you complete the level, Sugar Crush is activated and will score you additional points.
Striped candies that come out their cannons do not help because of their low spawn rate.
Any jelly fish that comes out of their cannons can get consumed by chocolate.
The spawn rate of the jelly fish is once every other move. This means that, without a jelly fish + colour bomb combo, this level won't be able to be completed until there are at most 2 moves left. Furthermore, at most 9 jelly fish will spawn, making it very difficult to combine with a colour bomb. Thus, it's likely that we need to clear the chocolate on our first or second move, which means that we either start with a possibility of making a striped candy or a cascade will activate a striped candy on our second move. The odds of that are very low. Thus, 18 moves are not enough to collect 8 jelly fish.