I just tested back, and it's a mistake from me. the problem i had were in the hard part and in think it was when i was holding S at the end of the platform, and just missed the jumps ^^' . The game goes so fast it's sometime hard see what exactly happened.
I didn't notice i just had to tap, but i think a tap is good. It's just very difficult for my brain to handle timing, how long to press the jump, and timing for the fall. I feel like it's harder if i use different hands too, it's unusual as a control for video game.
the only area were fall control were frustrating were the 2 last checkpoints, especially the first of the 2. I thinks it's because you need to time it along with the jump timing.