Ok, I was able to run your game in landscape mode.
1. Change "Fullscreen in browser" in C2 to "Scale inner" (letterbox scale was probably the cause of the black screen)
2. In Xcode, on the General tab, Device orientation, uncheck portrait/upside down and check Landscape Left and Landscape Right, or on or the other.
3. On the info tab, find "Initial interface orientation" and select "Landscape (left home button)" or right home button.
The game should run with these settings. Obviously some parts of the game will be outside of the screen depending on the screen ratio, but figuring a way to fix that is the beauty of supporting multiple screen sizes.