If you press any key your screen does what? Having a little problem unstanding your question so bare with be on this. The seconded part is when you press tab the screen changes or moves? When you press tab again the screen moves back?
Then the third part is when you continue to press he tab key then the game moves on the screen other wise it is like paused? Sorry about this but I am trying to understand what is going on.
This is what I see. You start the game but it is frozen on the screen but to get it to move you push the tab key and you have to do this all the time inorder to move the game along?
That is how I am reading this. Also could you post your spec's of your system like your CPU, GPU, RAM, and other hardwear. Get back to us with a answer. Again I am sorry for not understanding what you are tells us.