I don't know what it is but I like it.

This is so fun! Small games like this are really inspiring to me.
I fell in love at the first screenshot! The UI is exactly my cup of tea! I love ascii art, especially charts/graphs, etc. Did you use an existing framework/library or is the UI all original? I also really like the sfx, it sort of reminds me of the circle of fifths (I'm not a music person, I've just heard OF it) which is super cool!
Only thing I would ask for is more explanation of what the upgrades do and what the charts mean. Does SPS stand for "Score Per Second"? Also, I haven't gotten far enough to see any kind of "prestige" system yet, is there one?