Ristar/YMMV

Breather Level: The second zone of Planet Automaton is fairly straightforward, especially when compared with the Spikes of Doom-tastic first zone and the final showdown with Greedy.
Demonic Spiders: The only way to describe the enemies on Planet Automaton, they will hit you at least ONCE. That doesn't sound so bad until you realize you can only take four hits on the easiest difficulty setting...
The Jimmy Hart Version (sorta): "Busy Flare", the theme for the first part of Planet Scorch, starts off with a unique riff. Eighty years earlier, Manuel de Falla composed El Amor Brujo, which included a little bit called "Danza Ritual del Fuego"... which roughly means "Ritual Fire Dance". Seriously, listen to the opening motif of "Busy Flare" then the part of "Danza" linked here and draw your own conclusions.
Narm: The birds' singing in Planet Sonata.
That One Boss: Greedy. Oh my, Greedy.