Don't give up the day job
To be honest, this isn;t the sort of tune that you expect to hear while fighting a boss or even being introduced to one, even in an 8-bit gaming atmosphere.
It's a decent start, but after about 5-10 seconds, when it starts to go downhill, you need to reign it in and start conveying that the boss is big, is bad and is out to get you, rather than the fact that you're going to win. Themes for Bosses tend to be full of trepidation and fear, because these are the most stern of challenges that are going to be faced by a gamer in any given game.
[Review Request Club]