So while I've been doing the Famicom FNaF2 office, I was idea-engineering how to fix some of the problems with FNaF2, keeping in mind that I'm using office sprites for the hallway. Additionally, I was trying to think of ways to give the player more incentive to actually use the camera outside of warding off a single animatronic. So here goes my list of proposals if someone turns the released sprites into a game:

1) FOR THE LOVE OF GOD GET RID OF THE PUPPET
2) I'd also get rid of light switches. Animatronics from the hallway would slowly fade in accompanied by footstep audio cues, giving you a chance to throw your mask on before they get too close. Animatronics from the vents would just be there when you look at them.
3) In its place, I'd introduce The Light Zapper (like the NES one!). It would be an alternative to the mask in that instead of throwing the mask on, you could just shoot something that gets too close. You'd still have the mask, but the Zapper would be a lot safer to use.
4) To balance out the great power the zapper bestows, it is the only thing that can stop Foxy. You'd have to shoot any other animatronic twice to get them to leave. Additionally, you either have a shitty recharge rate or none at all (The AI would never allow Foxy to show up more times than the player has total shots).
5) Now to address the cameras. In FNaF1, the camera is pretty much only good for slowing down Foxy and Freddy, meaning at most you only have to keep tabs on two rooms. It's "simplified" in FNaF2 in that you only have to keep tabs on one room, but goddamn do you need to keep tabs on it. My proposal would be to have either another human in the building (ie: a night guard that actively patrols the facility) or a new animatronic (that the other ones don't recognize). You'd have to keep tabs on where he goes and protect him from the animatronics. His path will always be consistent, but the only way you can tell his position is by checking the cameras. There'd be an audio cue if he enters a room with an animatronic (maybe a digitzed "HELP!" or something) at which point you'd have to throw the camera up, look for him, and ward off the animatronic by using the camera's flashlight. This provides an incentive to check the cameras, as he's constantly moving, and you want to make sure that you have a rough idea of where he is when he gets in trouble.
6) So why would you be watching out for this guy? Well, if you let him get killed, the animatronics start getting into your office MUCH more frequently, to the point of it requiring lightning reflexes to survive.

I dunno, those are how I'd address the problems with FNaF2