Please forgive my lack of artistic ability, but here's my question: Consider that a skydiver, without using his parachute, were to fall exactly parallel to a giant curved slide that starts at $90\,^\circ$ perpendicular to the ground and gradually curves until it is parallel to the ground. Can he survive?
My thinking tells me that if I stood at the top of the slide and slid down, making sure to keep contact with the slide, I would (if the top of the slide was high enough) eventually get to almost terminal velocity, yet when the slide starts to curve I would begin to feel an increase in G-force and friction, but no impact and thus would survive.
So then, if I were to jump directly above the slide given that I had enough time to adjust myself to be perfectly aligned with the slide as it started to shallow, (or even better, if I was able to have my body or part of my body scraping the slide) the impact when the slide moves from 90 degrees to 89 degrees would be soft enough for me to survive - and so forth until I'm actually sliding and no longer falling with the slide.
Answer
The answer is Yes and your thinking is correct.
You try to differ between impact and sliding on a curve. In fact the impact is just a sudden large force, while a curved (e.i. circular) motion similarly applies a force, just much smaller but also over a longer period of time.
The key in surviving any fall is to reduce the force on your body at "impact". A pillow does that. A curved slide does that. And they both do it by extending the impact duration. Remember first Newton's 2nd law:
$$\sum\vec F=\frac{d\vec p}{dt}\approx \frac{\Delta\vec p}{\Delta t}$$
Smaller momentum change $\Delta \vec p$ (that would be smaller speed or lighter skydiver) or larger duration $\Delta t$ will reduce the total force. A soft material like a mattress will extend $\Delta t$. And a curved slide will as well, as you explain it yourself, cause the momentum change over a much longer period of time.
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