Earlier quoted context omitted.
Actually, flat. A learning curve usually is time on x-axis and knowledge-percentage on y-axis. If knowledge-percentage only slowly increases the curve is flat. A nearly vertical curve means you learn fast. This is a little bit like educating people about kerning [0]. For another example, a "quantum leap" is basically the smallest possible leap you can do. [0] http://xkcd.com/1015/
Or if by vertical he means running face first into a wall... Upvotes for both though...
I tried to start the game 5 times. The first 3 I could not even start a game. The 4th one I followed a tutorial and was able to start, and nothing else. The fifth time, I found Captnduck's excellent video tutorials ( http://www.youtube.com/watch?v=koZUS2h-Yzc ), and I was finally able to break into the game.
Then they added a whole layer of complexity to the military (with a lot of new UI quirks) and I just stopped playing.