Easter egg: The hidden clip entitled "Secret behind the scenes look at the animation department" can also be found on the 2-disc edition. On the second disc with the extras: highlight the choice 'gag reel' then press the right-arrow. The little circle between the menu blocks now glows red. Press enter-button to watch.
Easter egg: On the special collector's edition, in the Special Features second menu (go to Special Features then go to MORE - its the menu with the gag reel and deleted scenes) then press 1 on your remote. The EXTRA written on the upper-left of the newspaper should light up and you will get a 2 minute clip entitled "Secret behind the scenes look at the animation department, by Steve Meyer". There's a surprise ending so go watch it.
Chosen answer: About 95% is CGI. The only real part of the movie was the actors themselves (and small objects they handle), with the exception of Dr. Totenkopf, portrayed using archive footage of Laurence Olivier. Everything else was CGI.
Guy