I think that diagonal movement is fine, but what I don't like about the Zulite ganis is
1) it closely resembles Geodude and
2) the Zulite walks way too fast. It seems awkward controlling a creature who walks slow and moves fast, like some force is moving it other than the feet. And speaking of feet, if we gave the image feet it wouldn't look as much like Geodude.
And I have to argue about the pushing thing. I agree that teamwork is a major aspect of Graal, but how many people do you see who gladly volunteer to help out in the heart quest? It doesn't happen on any given day that one of the campaigns to get people over there is successful. I still think that if the player presses "a" when the Zulite isn't moving, it just kind of curls up, but when the Zulite has been moving for quite a while in one direction, it starts rolling when the button is pressed. Maybe for some walls or doors where not even unassisted rolling works to break down (in some quests maybe), maybe we could institute pushing?