I've seen board games for LOTR and G.R.R. Martin's "Song of Ice and Fire", now Gormenghast gets the game treatment: Over here. Unfortunately, the company is based in the UK and the prices are in Pounds, so I'm not sure how that would work out, or if they have a means for overseas shipping/currency exchanges. Still, it's most fascinating, and it appears to be "licensed", since it was made with the blessing of the Estate of Mervyn Peake.
Hello, it's available through Amazon.com. I think I know what I want for Christmas this year!