✔ 最佳答案
The video on Youtube is probably a version written by the pianist herself, but that's a pretty simple one.
Since you 絕對唔要簡易版, I will give you a really hard one. The Italian pianist/composer Ferruccio Busoni (1866 - 1924) wrote one called Turandots Frauengemach (or Turandot's Room in English). A little 3 1/2-minute piece that starts with an introduction then the Green Sleeves - but quite difficult, be fore warned. Not many people in the world know about the piece, and even less ever played it. If you can play it, you're probably the first in Hong Kong.
You can find a score published by Dover: Busoni, the Complete Elegies and the Six Sonatinas. About US$20, should be able to find it in your nearby Parsons or Tom Lee.