There are only 19 colour bombs given to you. It is very difficult to make six more colour bombs to collect 25 in just 20 moves.
With the moon scale in effect, activating colour bombs can be dangerous, even though the scale is moderately stable.
The moon struck only lasts for one move, and this is the only brief period which will generate many colour bombs at once for you, or do absolutely nothing but make things worse.
This level is heavily based on luck. Although it is listed as extremely hard, some players may be able to finish this level on the first try, some may need weeks. On average, it will be hard, so it is not a variable level.
The orders are worth 25,000 points. Hence, an additional 5,000 points are required to earn one star.