Episode writer Heny Gilroy gives his insight on creating Grievous' lair:
“I went back to the old serials of the 1930s and looked at the terrible old places they used to create for the villains,” Gilroy says. “They were houses full of booby traps and monsters, with eyes knocked out of the paintings so the villain could look through and spy. It was fun to explore the home of the bad guy, to create a place so terrible that even the hero doesn’t want to be in there.
“It’s a great set-up because when the Jedi arrive, they’re expecting to find Nute Gunray – they don’t realize they’re in the lair of Grievous. From that point on, once they’re inside and realize they can’t get out, it’s basically a struggle to survive.”
“Kit isn’t one of the most serious Jedi. He tends to be more jovial,” Gilroy says. “To put him in a dire, life-or-death situation makes for a fun adventure because he tends to look on the more positive, naturally humorous side. Dread kind of rolls off him.”
Here's a clip of the episode sent to us from Lucasfilm: