The physics engine we are using is Rapier 3D which does a lot of the heavy lifting, even though we had to tweak a lot the physics properties of the ball and surfaces in order to get something that felt right. For hotspots specifically, we implemented the magnet-like effect with custom code (by applying a force that pushes the ball toward the center and slowing it down at the same time) as there is no attractor primitive in Rapier.

The dual input is indeed a consequence of our isometric-view design choice, which I agree may not be the easiest way to control the ball. But the 45 degree angle just looks cooler in our opinion.