Piano Sad

Hi just did this piece I wanted to do in an 8 bit style and would like to have feedback,  Its not finished yet as I want to mess with the dynamics some more but what do you think? 

I think it could be a great soundtrack for a computer game.

What did you have in your mind when you composed it?

Could you please add a music sheet to this post, so I can help you more?

I can't really tell notes by ear, so I can't tell you my opinion about anything but the general sound and feel of it.

I think its quite suitable for a video game BGM too. 
It's nice composed but i feel mystery emotion instead of sad...