Neat concept! I find pretty rare the games with ghost as main character, and your game uses well this theme! Also, one of the strength for me, it is the controlling which is really fast to get used to.
The only things that I think that you can improve:
- I found the controls quite stiff, before playing your game I thought that the controls will be light and smooth, because we control a ghost, so for me it should feel like this.
- The music is a little annoying for me (But I think that it is surely my taste ^^")
But, overall really good work!