Originally, I had ten bosses planned out. I was basing it off the Ten Brothers from the Chinese folklore. But as I was trying to give them each different techniques and powers. It was really difficult.
10 bosses * 4 powers = 40 techs.
But nonetheless, I completed it. The ball busting was the level design.
In the beginning, I was thinking about 5 levels for each stage, so 50.
I was about 2/3 way when I said enough is enough. I had more than enough material anyway.
So I decided stop designing levels and I went on to compress the powers. It made my compact bosses more unique in the end anyway. So no more work and looks awesome. Mission accomplished.