@Hulaa, have you tried re-verifying files and all the normal work-arounds? Does your computer have the needed specs to run the game?
EDIT: I left it to download overnight - Not only does it work a hell of a lot better than it used to, it also looks absolutely stunning. Thanks so much, people of JAW!
My only criticism is that you can't customise graphical settings as much as you can in normal PC games (texture quality, shadows, draw distance, shaders on or off, etc) which may give problems for people with slower PCs (Magicka gave me this problem when I had my old graphics card), but I suppose setting v-sync, resolution and anti-aliasing is enough.