I didn't know there was a game. The movie is great, but it focuses on the crime plot and unfortunately leaves most of the historical/philosophical/linguistic meat out, which is not surprising when you compress a 500 page book into a 100 page screenplay. I guess an adventure game would actually be more suitable for incorporating some of the things the film left out.
The game is called La AbadÃa del Crimen and as far as I know was only released in Spain and never translated to any other language, so even though it is a cult classic in Spain, it is pretty much unknown outside.