I only had three more levels left to do, it seemed. Level 28 was a real pain, 29 was quite hard, and 30 (the last one) was actually pretty simple, if a little brain bending due to the gravity effects of so many planets in orbit around each other.
So then there was the credits, and now it seems I’ve unlocked some Extra Mode levels. Hurrah! I didn’t actually want it so end so soon!