In my app, whenever a game is completed it pops up saying to buy the full version for all difficulties of the game, this WAS allowed.
The part that was rejected was when on my difficulty select page, I had the buttons available for medium, hard and expert, but when the user clicked them it said "sorry, buy the full version for this!"
the email i received said that showing the user features that weren't there was against regulations. So it's definitely touchy and depends on the reviewer
