The issue with these kind of porting is edge case bugs - far smaller project/physic simulation has hit the same thing especially when original code isn't exactly clean, or sometimes only worked because of a logic bug.

This means you can play for maybe 10 minutes on the happy path but just as you are getting into the zone either a CTD or some strange event would make the game/simulation unplayable.

And while debugging is made easier, it's much more effort than telling the model to convert the code. Hence it's usually not done in these demos.