Given the task of creating a rapid prototype using an existing IP, our five-person team dove into the Watchmen canon and immediately gravitated to two things - the ARCHIE vessel, and the Giant Squid. The Squid does not appear in the film, but is the climactic destructive force in the graphic novel. We felt that using this creature would up the cool factor of our game and offer a fun arcade experience that anyone would be attracted to.
The addition of an ironic situation where the people you are saving are, in effect, getting in your way and complaining to you (see design document), fits right in with the persona of the IP and the worldview of its most sympathetic character - Rorschach.
My contributions include:
Take a look at my original design document here.