The US$9.99 is worth it though, especially since the real dollar (Aussie) is nearly at parity.
As I said, I've become hooked.
What I have found is the following:
- The hardest song that I have encountered is "Million Way of Drum" by Force of Nature. I guess that's how the game engine designates blocks and such because there are millions of them since the song is basically, as the name suggests, drums (there is a bass guitar in it for a little bit as well).
- The songs "Kalinka" and "Korobelniki" as sung by the Russian Red Army Choir give plenty of red blocks.
- I haven't tried it yet but I think that it would be entirely possible to listen to say Skeptoid while you play. I don't know if it recognises a difference between podcasts and songs.
- No matter how obscure you think something is, there will usually be someone who already holds the #1 spot.