Number 1 - This one is very good, though the back temple looks a bit confusing and the terrain overall lacks terrain textures.
Number 2 - Almost the same problem as 1, though this one REALLY lacks ground-texture variation. The door on the right is clearly not sticking to the building. And what are those hovering things near the Arcane Observatories?
Number 3 - Not a lot of customs and a natural feeling, I guess I approve of this one.
Number 4 - Pretty good, I have next to nothing to comment on.
Number 5 - A familiar scene. But the sky was clearly a sunset, in yours it's noon. The idea of the red glow was probably the sun, but because of the sky, it failed. It also appears to be near the camera.
Number 6 - Mushroom world... that's strange, but I guess it worked well.
13/15 for the whole pack. Very impressing, though.