Hi sorenkahl! Good question! Thank you for uploading your world, and I have now changed it so now the ball will role down the hill, and have a rolling animation!
What I did was change the rolling method to where I altered the 'do together' code slightly, making the sphere move down 3.5 meters, belong side moving backward. This made it gently go down the hill, but doing so I still needed to incorporate the rolling animation as you had made earlier (to make it look realistic)
. So then I created a copy of that sphere, which would vehicle the sphere that's actually moving, set the original sphere to 0% opacity, and made the new sphere have a roll animation in the roll method still.
And that's what I did! You can download it below and it's ready to go! Bye!