Some attention to detail I've liked and want to note before I forget:
covered trucks can't benefit from timefall shelters but crappy, uncovered MULE trucks can
if you walk a path in the snow frequently, the snow wears down and the dirt becomes visible, improving it
Some things that surprise me because Kojima DIDN'T include them (yet?):
The inability to pick up chiralium crystals by driving over them with a vehicle. Such a waste of time to stop, get out, walk ten feet, pick up crystal, walk back and start driving, drive another 20 feet, repeat ad nauseum. Just do it in a Mario Kart way and make up some technobabble to explain why it's happening, like an obverse vacuum exhaust nozzle (OXEN).
Rifles apparently can be upgraded with scopes, but they're cosmetic or something? Got my hopes up for nothin'.
---
Take me down from the ridge where the summer ends And watch the city spread out just like a jet's flame