Secret Agent Clank appears to be the only game I could find which has it's content stored in plain zip files so here are the extracted content which appear to be .cooked files I have tried looking at reversing however I can't seen to find a good way could someone assist?
Content Sample:
https://dl.dropboxusercontent.com/u/107 ... d_files.7z
Example of one of the files open in hex editor

As you can see there are some references to texture files in there.