Level 31 is the eleventh level in Lemonade Lake and the 16th jelly level. To pass this level, you must clear 8 single and 33 double jelly squares in 15 moves or fewer.
When you complete the level, Sugar Crush is activated and will score you additional points.
The presence of three colours makes it easy to create special candies and is essential as special candies must be used to clear the jellies.
The jellies are worth 74,000 points. Hence, the two star requirement is automatically collected and an additional 24,000 points for the three star requirement to be earned through matching of candies.
The jellies can only be cleared by using special candies created from the bottom rows. Moreover, none of the rows and columns where the jellies are have three horizontal or vertical squares. Hence, cascades that score a great many points are impossible.
With respect to the three star target score, 15 moves and three candy colours, it is much better if cascades which may detonate special candies especially colour bombs are created than relying on sugar crush to meet those target scores.
With only 15 moves available, sugar crush is almost worthless with respect to the three star target score. Hence, try to create as many special candies and cascades as possible as they are worth many more points.