Level 9876 is the first level in Soda Sea and the 2089th candy order level. To pass this level, you must collect 72 toffee swirls and 20 dark chocolate layers in 22 moves or fewer.
When you complete the level, Sugar Crush is activated and will score you additional points.
This is the last 4 digit level whose digits form a decending sequence (and almost certainly the last level in the game where this happens). The next level whose digits form a decending sequence will be Level 54321, the first level in Episode 3623 (which, if the current trend continues, won't be released until Summer 2040).
However, if zero is counted as a digit, then the next level would be Level 43210, the 5th level in Episode 2883 (if the current trend continues, this level wouldn’t come until late September 2029).