Ron Gilbert has finally spilled the beans about his story idea for Monkey
Island 3 in the British game magazine, GameZpire. Here is a section from the article:
"Three words: 3D ice levels. I always had it in my head that the third and final Monkey Island game would be completely rendered in 3D. Guybrush would find himself in the midst of a terrible Carribean snowstorm. The ocean would be completely frozen over, and Guybrush has to navigate across to get back home. The interesting thing about that was to have the physics engine work in overtime. Imagine, as Guybrush approaches a steep cliff, he just can't stop and he slips right over the edge... because he's walking on ice! Other games might have used an idea like this in the past, but I came up with the idea first. I just never got to do it. And this is before 3D games were even the norm! Maybe someday LucasArts will sell me Monkey Island and I can do it right. Of course, the game would end up back in a carnival, since that was the original secret. I can just hear the internet fans complaining now that it's out in the open."