The original four-star version consisted of 3 instead of 4 moves. A 4th move was added to upgrade this puzzle to five stars after bumping 4-2 down to four stars. I regretted this change.

After going through it multiple times to verify the correctness of the puzzle, one step was forgotten: to account for the drop during the color bomb move, as the middle column stays still while the other four columns drop one. Due to the complexity of making a new puzzle, the errata was kept but announced.