From the introduction:
You hummed the tune, you've watched the movie and you've played with the Dinky toy. Now, you too can dive into the wild and crazy world of Yellow Submarine, the roleplaying adventure
This is a one-off game, for four imaginative players and an experienced GM, who is capable of 'winging it'. The GM should certainly have seen the film, but it doesn't really matter whether the players have or not. It's a good idea to play Beatles and other period music in the background during the game, but the ingestion of dubious substances is strictly up to you. Remember, rolling dice when stoned can make it very difficult to add 2+2.