It's not about hard. I play many games that are hard.
It's about depth. The whole game is just a shooter with a white/black bullet system. Yes, that's a twist on the standard shooter, but it's a 10 degree twist. I would rather play something like R-Type or Gradius (in terms of shooters), where I had options in weaponry. Even then, I'm kinda done with shooters, having played enough of them when I was a kid.
Rosalina: But you didn't.
Robert: But I DON'T.
Rosalina: You sure that's right?
Robert: I was going to HAVE told you they'd come?
Rosalina: No.
Robert: The subjunctive?
Rosalina: That's not the subjunctive.
Robert: I don't think the syntax has been invented yet.
Rosalina: It would have had to have had been.
Robert: Had to have...had...been? That can't be right.