Not being able to scroll back up is definitely a first for me.
Nor being able to use page up/down. :(
I'm not sure why they don't start with the navigation map, instead of the wonky scrolling experience. You have to hunt for the map, but the link to it is just below the title screen. The map is actually well designed!
It's like taking a tour of the Smithsonian, but only being allowed to view it through a paper towel tube.