Collect a Yin Yang
Collect all the Yin Yangs in World 1
Complete World 2
Complete World 1
Collect all the Yin Yangs in World 4
Collect all the Yin Yangs in World 3
Collect all the Yin Yangs in World 2
Complete World 4
Complete World 3
Collect all Yin Yangs
Reach a level starting from a different one