N++, like the other N games before it (Ncestors? Ntecedents?) is hard. In fact, this time, there are "evil ninjas" chasing you in some levels. These ninjas are, in fact, you from two seconds ago and you from four seconds ago, etc. They're not in all of the upcoming PS4 game's 1000 levels, but they are in some.
I shot a short video of these past selves bedeviling a gamer at E3. Poor guy!
N++ is coming to the PlayStation 4 later this year.