Genuinely the no hit run is the most hellish ass cheeks clap factory someone will go through on mobile, you have to pay attention to THREE torturous things at once; the horizontal knifes, the Vertical knifes and the RNG on Chara's slice position making you suffer the great risk of getting damaged if you ever stand idle, if you are on the sliding blades mere seconds about to switch sides you are completely DONE if either chara lays a hit if you dare to go to the other side or you get hit by the 2d knife breathing down on your neck.
I personally don't find harsh neither that or the chain constantly pulling you while deliberately giving your best to dodge the slices, but the RNG completely leaves me butt naked mainly when i position myself to not get sniped and the evil light brown bar starts to lay above me to crack my run for good. After legit 30 tries around 2 hours I have to admit you are totally at the mercy of RNG if you wanna get that scene.
The best i can provide is using the pill bottle AFTER you somehow manage to fill up the love bar and pray for the Saint Mary to not get clapped at the final fight, you don't wanna go again for a round 2 bonus. Never in my lifetime i expected a goon game to completely tear my skull in half of so much internal fury despite managing to get all the other scenes, and i did not even accomplished that scenario a single time.