The version I have only has one difficulty level. Hard.
Yet, I've heard that there is a Medium, Very Hard, and Impossible difficulty level, and each time I start a new game, it only gives me the option to start on Hard, which it automatically sets me to.
I watched cloud8745's videos, and he said there were other difficulties too, so is there any difference in my version compared to others? I don't want to reach a certain point and not be able to go any further. That would suck some major balls. :(