I started with a test in Flash, separating the body parts out. I took inspiration from the artist, NCH, and the animation style of Shank. I drew up a character based on my last animation that ended up turning into League of Legends's Poppy (it was all because of the hair).
We decided on Unity so we could easily swap out pieces, in case we later wanted to do some sort of customization system. While David was working on the programming and Ryoma was working on the concepts, I decided to figure out Unity's new 2D system with animation.
Late in the process, I realized I could group objects together (such as the head elements) so I could translate/rotate them together (which would have made the head animation cleaner). I should have split the torso into two, so I could do bends there; the root of this problem is shown in the attack test.
Also, we had originally intended to keep the framerate low for style reasons (the attack and the idle look okay like this), but Unity doesn't handle stepped animation perfectly, sometimes tweening the frames in the wrong place, or just completely wonking out.