To be honest, I am not worried about being limited by red fields. In fact in Drakan, you couldn't fly wherever you wanted because you were most of the time inside canyons and not able to fly above them.
I am worried about not being able to fry ground targets. I've just seen a vid of DD2. The player was attacking a goblin camp and when he turned into a dragon the goblins disappeared. He fired some fireballs that done nothing, and remorphed into human, and the goblins appeared again, unharmed
That sucks.
It's easy to limit experience gained by the dragon when killing ground targets.
