Literature is the best medium compared to anime or real-life movie.
Imagine Ryo becomes a poorly-rendered anime hero who KICKS ASS, or, a movie star running around asking people for hints. Any commercial anime/movie adaptation of this game will kill the originality of it simply because: Shenmue is not even moderately commercialized. If they can have the budget for a CG movie, I'm sure they can have the same financial power to release the game. So a novel is the only medium which can give you the last chance for imagination if the game fails to come out. Support it.