I heard the issue is with Hayao Miyazaki, who directed the film that most of the animation was taken from. He apparently wasn't happy with the repurposing of his film, which was done without his permission. I don't know if he seued them, or if would-be porters don't want to get on the bad side of one of animation's most powerful figures. Honestly, I think it's an opportunity to introduce more people to his work. I bought Castle of Caliostro on DVD many years ago because of the Cliffhanger connection. I otherwise would have never even heard of it. I enjoyed it so much I sought out his other worms, like Spirited Away and Howl's Moving Castle.
LOL, my history is similar, as I was introduce to Lupin III specifically because of this game, and even my son now has interest in that character for the same reasons(Recently learned of CH history). I wonder if the director has any ownership in the rights, or if it's a pleasantry being given by someone? Spielberg directed Jaws, and if Universal decides tomorrow to remake, reboot, or otherwise, Spielberg wishes go out the window. Of course Universal still has HUGE respect for him, so they stay clear for those reasons, but not for any legal ones.
I'm pretty sure Stern acquired some form of rights at the time, but how well done, or proper, is anyone's guess? I've never held out much hope to ever see this, as there's way to many "chiefs" in this equation, and not nearly enough Indians. Sadly at the end of the day, it would take a super fan with a huge bankroll to make CH happen, as it's just not worth to most. Even if it could do DL numbers, which is impossible, most of the potential profits would probably have to go to X, Y & Z to get approval, and then what's left?
Scott Pilgrim is finally coming back in to gaming, but the demand made whatever needed to be paid to make it happen, worth it to all involved, and CH just isn't that type of game. Me and you would love it, but probably not many others, especially for the current asking price, for a FMV game that almost no one has any meaningful memories of.