You asked for a line, they gave you a line, what more can be asked for?
We used to intentionally add wrong data to our datasets so we could circle it afterwards, declare it “outlying data” and gain the extra points for spotting and documenting it.
I’m not bitter about my formal education, honest…
https://en.m.wikipedia.org/wiki/Frets_on_Fire
It’s been available since 2006, works very well