The exit - from the trailer
I just noticed, in the trailer, the exit chute/shaft/water ride is different to that in the film.
http://www.imdb.com/video/imdb/vi543359001/
Pause at 1:33-1:35
It looks like a long, metal chute, rather than some silly water fall drop/cavern system.
That would've made much more sense, plus it probably would've been cheaper to do, rather than use dodgy CGI visuals, hehe