I think I see what you did here and I like it. So at first I tried moving my fingers in a sequence of SDF(left hand) then LKJ(right hand) but then I realized I'm moving backwards. Sooooo what I did was I crossed my hands to roll my the keys FDS(Right Hand) and JKL(Left Hand) THEN I WAS MOVING BABY! Cool little twist :D Little mechnaic but great effect :D Nice work.