Cómo cambiar rotar con la unidad de script
var rotationVector = transform.rotation.eulerAngles;
rotationVector.z = 0; //this number is the degree of rotation around Z Axis
transform.rotation = Quaternion.Euler(rotationVector);
//if you put this in a coroutine and yielding for some amount of time
//you can have something like a rotating loading icon
Powerful Porpoise