By videos I don't mean a particular format, I mean an animation that takes the whole screen, like the Foxy chase scenes.
While we're on the subject of animation, I'd like to point out that the DS gets all worked up and sweaty processing a small .GIF, let alone a long full screen one - it's generally not great with rasters, that's why people use tiled sprites which are far more lightweigh - the DS was designed to work with those, full Bitmaps are harder to work with.
I'd also like to point out that I don't mean to discourage, rather I'm suggesting picking realistic goals. I do not doubt anyone's skills in programing, I just very much doubt that the DS has enough memory and juice to handle a 1:1 FNAF port without some serious coding gymnastics.