I'm running into trouble with the part1 folder where the [Game] file refuses to be extracted. I'm just using Windows' standard Extract function from the right-click menu; it doesn't have any trouble with part2, but part1 keeps running into an error. I'm currently going through your SubscribeStar/MegaNZ link to see if the single-file download runs into any of the same problems, though that's more of a potential workaround than a proper solution.
EDIT: Nope, the MegaNZ download runs into the same problem.