If the developers stick to a vaguely physical model of play, Mortal Engines style vehicles aren’t going to work. Even once you solve for problems such as raw power, ground pressure and traction, you’re ultimately going to come up against pure material strength.
The larger a vehicle gets, the more devastating its collisions get compared to the potential tensile strength of its frame/hull. At a certain point even carefully engineered reinforced steel just isn’t strong enough any more and the moment your 500,000 ton vehicle impacts something comparatively solid (like a slope or rock face), the forward hull or suspension is just going to crush like an eggshell.
This is why even heavily armored warships can be badly damaged or outright hulled by modest collisions - their momentum simply vastly overpowers their armored hulls and they crush like tin cans. It’s an application of the square-cube law where mass increases exponentially faster than surface area with an increase in volume.
You can see the inverse application of this law with tiny insects. You can flick an ant off of you with an amount of force that will vastly out-measure anything the little guy has ever experienced, and it will very likely remain completely unharmed. In this case his mass is so small compared to his surface area that acceleration force your utterly massive finger applies against him does not significantly challenge the structural strength of his exoskeleton.
