I'll be away from my computer for a couple of days, so I thought I'd get this out tonight. With luck I'll be able to get to another post by Wednesday, if not Tuesday night.
Big Pig is the first level in the next chapter, GenCorp. GenCorp is a rival corporation of CyberCorp, our "benevelolent" employer. There's a bit more to this rivalry outlined in the manual, but suffice it to say that we're not exactly taking their offer of assistance at face value. For now we'll graciously accept their assistance in dealing with the aliens (do we have a choice?), but we'll always watch our back. It won't be long before we'll be fighting againt their elite troops and robots.
The Spoiler Guide referst to Big Pig as straightforward - "about as straightforward as they can get". I guess someone had a sense of humor, as I still don't particularly see the paradigm of find switch, then retrace steps and search all over for the new open door or moving platform, to be straightforward. In any case, if you kill everything, flip every switch and explore everywhere, you'll eventually get to the final terminal and if you've really exterminated the aliens, be taken to Burn! Burn! Burn! But more on that next time.