Quote Originally Posted by EricLang
Now you get me really confused. I know the Windows API is extremely slow, when it comes to drawing to the screen.
Define "slow"? Actually, I think Windows API is quite fast and efficient. Are you sure that your performance bottleneck is API itself and not your code?

If I were you, I would store the game pixel map in a large bitmap; when drawing on the screen, I would draw only subset of such bitmap. For modifying map, I would simply get direct access to all pixels and modify them once per frame. You won't get 500 FPS this way, but for what you need it's one of the best approaches.