I spend a short time with the "The Dangerous Descent" Survival Challenge. I could have easily lasted longer (scores in the 4000 to 6000 range and survival times of three or more minutes are pretty realistic targets), but playing (and viewing!) this level rapidly gets repetitive, so I just cut it off at the point where I accidentally died during a fairly short run.
This level is alright though it is also another Challenge that contains pretty simple gameplay. I much prefer the (similar, but in my opinion better) Metropolis area Score Challenge known as "Elevation".