Some hints to make it not sound like my 5 year old
1. If you take a sad and beautiful song, don't leave out the chords. Makes it sound less sad and sorrowful.
2. Actually play the song instead of putting it into a sequencer, human offbeats and dynamic tempos are important in sad songs.
3. Get a better piano sound. It sounds as if someone it literally slamming the keys with a fff dynamic. Trust me, it's not really sad and sorrowful, more of mad and horrible.
4. Try to change up some of the notes. Just copying note from note gets boring and gets nowhere fast.
Honestly, I don't know how this made it to the top songs.