I got bored and found this video on youtube. I played a bit of Stepmania back in my school days but now that I look at it...these kinds of steps look almost impossible to do if you were to actually dance to it. Anyway this song is an astonishing 15 minutes long so it's split into two videos...oh and it's on autoplay.
(Try to do these steps on your keyboard if you want to XD)

Please watch both in HQ for better sound ^^

Part 1

Part 2