Synergy:
I took a good look at it, and it is alot simpler than it looks when you first see it. But its still really good :)
Synergy:
I think you should find a way to automatically clear a piece that is written over. Unless I was using it wrong, I had to clear it then move my piece.
Synergy:
Also find a way to restrict movement so that you can only move pieces where they would normally be allowed to go. Eg bishop only diagonal.