I really liked the old city concept with it's bunch of history and traps, in addition to the race against the clock, but...
Why on earth the PC would like to go to this extraordinary dangerous place, with inspiring names as Isle of Terror and so ?
Just because Reginar, one barely known pathfinder, asks ?
For the adventure spirit ?
If your players are naive or gentle, it could work, but the involvement will be rather low.
To play this scenario, you will have to think about why low level young adults would have to go to one of the most dangerous place in the world...
That's why the only 3 stars, as PC involvment has been, IMHO, sacrified there.
