Every time you complete a level , the black magic expand getting much powerful.
Your only way to defeat the black magic is to collect the 4 colors: Red, White, Green and Yellow, and combine them for the last level, "Corrupted zone" .
You can find an color at the end of the level: Red = Nether White = Winter Green = Plains Yellow = Desert.
After you complete all of the levels, the colors will combine unleashing an power that can transform the black magic into an "Corrupted zone" to give you a chance to finally beat the black magic!