i wonder the same, Novacoders comment questioning the physics requirements surprised me.
Moving graphics has to be more demanding then predicting where to move them. I think the MD version is limited only by the coders ability (no offence) or time applied.
Mega drive is tile based & all the rotated graphics would have to be pre-rendered. So moving them is not a problem at all.
Realistic physics calculations are very complicated. You might have a disorganised structure that is barely able to support itself and then something light falls onto it and it will collapse. When objects touch you have to calculate the amount of force and the direction of it, but there may or may not be an opposing force that stops it from moving. Imagine you have a tall object and then a short object, if something is moving horizontally and hits the top of the tall object then the tall object will start spinning as the bottom can't move & it will also alter the trajectory of the horizontally moving object.
I believe he could fake something better than what is there now, I don't expect to get anything like the original.