The op is right. This is truly 5h or under. I just completed this and it took me about 4.5-5h to 1k.
The game didn't slow down or atleast I didn't notice it. I used turbo controller to get 10k A button achievement (which didn't take long) and as soon as I got that, I changed to auto skip mode + rubber band. That is alot faster way than pushing A, even with the turbo controller.