...You should definitely try some of the less touristy (yes, that is possible in Stone Town) places.
Beyond the name, don't expect much Freddie Mercury in this bar. I visited this bar with a group of friends one evening, there was live music -not even Mercury's style of music- blaring out at a ridiculous volume for such a small restaurant area which made conversation very difficult. The food itself was OK but nothing to write home about.
Considering the wide variety of food available to you on such a beautiful island of spices and fish, it was probably a meal wasted in my opinion. I'd encourage anyone visiting Zanzibar to look around for a more local experience: it's not hard to find nicer places that'll cost you less, probably be a lot nicer and probably give you fonder memories to bring home with you.