Most things remain the same from the original story. But theres a couple of new additions!  
On one hand, since The Moon is part of one of the major worlds within the book, it had to have its own Lunar Castle, so that the rulers may have a place to gather and govern. A little Lunar Town also formed around this castle, since many background characters decided to move to The Moon.  
You think the castle is a great addition, as you can now play pretty pony princesses anytime you want!  
On the other hand, theres the Teleportation Center, used as means of transportation between the surface and the underwater Moon. Talented unicorns work here, but it is now in close down since the attack on the Lunar Maria.  
Hence why you had to rocket your way in and out of The Moon.