But the app has the Hardcore deck which seems pretty good if you want more difficult cards? Also given the time-pressured aspect it doesn't really matter how good you are at building your ship if your opponent is competitive since it's all relative.
There is just a lot more variety with Rough Roads to make each round different, and with more different kinds of components so you can build more different kinds of ships. It's harder to survive to the end, also, but that's not necessarily the point as much as making the game more varied and less repetitive. With the standard game and the standard rules you're pretty much building the same ship every time. Sure, there's some variation based on the cards you see, but with the base components there's not that much different you can do from one round to the next anyway.