Feels like something is missing, but thats okay!
I loved the beat of it, I enjoyed that. Unfortunately though, I couldn't help but consider until 1:12 to be nothing more than a drawn out intro, as it got worn out to fast, it needs to be mixed up. 1:12 is where it got really good and got me somewhat excited...until it kinda faded out at 1:40 again. That part I'm fine with.
If I were to suggest a solution in my tastes, I'd use more of the chunk between 1:12 and 1:40, and if you were to keep the rest, add some sort of melody to keep it not so shallow. When I was listening to it, I couldn't help but think really fast paced piano (or something of the like) would add a lot of flavor to it.
Its a nice job, but it feels nothing more than a base for something that could be more epic (especially since its titled Boss Battle). Keep it up though!
Ookami-Kun 
