The plains start very abruptly... There needs to be some sort of transition between the two. Also, the ground to be in a radically different style compared to the rest of the land. Perhaps try to make it more... eh... I dunno, i just doesn't feel right to me.

Other then that, very nicely done. I love how the ice caps look... Although I like the icecaps of the first version better. It might be less realistic, but the first one looks a lot nicer (IMO).