You won't believe this: it _is_ playable on mobile! I see a lot of people playing this on their phones and iPads.
I contemplated adding gyro controls, like in "Marble Blast Mobile" from back in the day, but they are very imprecise and don't really scale well to high-level play. With the current d-pad controls, there's actually a mobile player who holds the world record on many levels. Never would've expected mobile controls to scale this far.
A. Was playable on mobile
B. Could use the phone's gyroscope for controlling the ball