I believe Seas of Blood and Rebel Planet were made into Commodore 64 text adventure games with some graphics.
As was Temple of Terror, which had no graphics.
Part of me wonders what a Fighting Fantasy gamebook would be like as a more modern RPG since there are encounters and turn-based combat built into the books. However, another part of me likes them just fine as books and I can use my imagination to create the visual environments of the adventures.
Deathtrap Dungeon was released for PS1 as an action style game, rather than an RPG.
It sucked. I hate to say it, but it sucked.
I really wanted to like it....but it sucked.
And it probably killed any future development of FF books into games.
You're right. It would be much better as an RPG.
Problem is that you're solo in most books - rather than having a party.
Could work though.