There is plenty of wall - jumping and object - smashing, but puzzles also abound, usually in the form of one of many hidden challenge rooms. (gameplanet.com.au)
There are also a few hidden challenge rooms and even some extra challenge rooms that may be unlocked only through special codes. (gamerstemple.com)
«Ocean warming may well turn out to be the greatest hidden challenge of our generation,» said Dan Laffoley, marine vice chairman of the World Commission on Protected Areas at IUCN. (scientificamerican.com)