Donut Plains had such great music I think. It was a true break from most of the other music you heard as well while playing the game too. It also had some good level designs as well.
The drums are cool and give a hip feel to the song I think. The keyboard has a high feeling to it that makes this piece feel nice and simple too. Then you have the bass line simply going back and forth between two notes making the tune complete.
Overall, very nice piece of work.