"I don't really know how to answer that, because I've never been asked to do it. That's fine, though. If you're playing Luke the way he was in the films - from his late teens to mid-'20s - I've outgrown the role. In the story, Luke is so boy-next-door farm boy, it's like Dorothy in Oz. All the other characters that surround him are fantastic."
He pauses for thought. "I'm not sure when George's animated series Clone Wars is set, but I think it's before Luke was born. Maybe when he was an infant." Perhaps, then, he could provide infant sounds? "Yeah, whimpering myself to sleep at night."
With Luke put to rest, Hamill became known for portraying another icon, albeit one that'd have the Star Wars hero quivering in his toga.
Throughout the '90s, he played Joker in Batman: The Animated Series, reviving the role in various spin-offs, and for the 2001 game Batman: Vengeance.
"I played Joker from 1992 to 2004 in all the animated versions, including the feature films," he says. "I stopped in 2004 and didn't expect to return to him, so when they asked me to come back I was curious." The return of the Animated Series' Kevin Conroy as Batman and Arleen Sorkin as Harley Quinn, alongside the writing talents of Lost's Paul Dini to Arkham Asylum convinced him to sign up.
"I thought this will be one last chance to play Joker. And it was so much fun to play a character who is clearly insane." So what does Hamill think drives Batman's foe? "I'm an old school comic book fan and I thought Heath Ledger was brilliant in The Dark Knight: a harrowing interpretation with a complete lack of joy. But I think Joker has a huge ego, and he's almost angry that Batman is obstructing his ascent. He believes he deserves acclaim for his genius."
In Hollywood, Hamill must meet people like that all the time. "Absolutely, but all these things are exaggerations of real life." Having acted in film, TV, theatre and animation, Hamill is not giving up on games. His next project, Black Pearl, is based on a run of comics he wrote in the '90s, and there's an animated movie in the works. The actor could have retired to bask in Star Wars glory years ago, but his love of the job keeps him going.
He laughs again, only this time not in the manner of a terrifying lunatic. "The minute I get jaded is the minute I don't get out of my pyjamas."