I still can't even break through, around here, let alone solve it in 660. It's a great puzzle, IMO!
Will be back!
EDIT (the next day): Today I finally saw what to do and got it to 6 off, where Yokosooo also stands, I see. Will try to find the last 6 steps, as well (not sure, why I couldn't see how to set up things to make way, before).
EDIT2 (about half an hour later): Looking for the last 2 steps, now. Where could they be?
EDIT3 (another half an hour later): In search of two steps I now found four.
Enjoyed it a lot!