Those fanmade chiptunes are extremely fitting to the boss

Hayabusa's evolved form works well here because of his anti-alien targeting and immunity to slow.

This reminds me of the Adventure Time mashup in Minecraft. It just sounds so much like it.

more like

The Battle Cats: Aku battle theme

this track is made by SarothCyngus

he makes some cool chip-tune tracks
https://www.youtube.com/user/SarothCyngus

A remix of the Brobot battle theme from Super Paper Mario. 

Just who is that mysterious masked man?

are you lost in life like i am?
\/ This might help you \/
https://www.youtube.com/watch?v=V8rzJjayyAo