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 6740 is the fifteenth and last level in Floaty Fortress and the 1639th mixed mode level (599th jelly-order). To pass this level, you must clear 81 double jelly squares, collect 135 rainbow twist layers and 12 magic mixers in 25 moves or fewer.
When you complete the level, Sugar Crush is activated and will score you additional points.