Came across Bullet Age today and then found my way here. Love your art. Very clean, silhouettes read well, colors pop. Good stuff! Wanted to ask what you're using for animation.
I did work on an indie game once and they had me create each frame as a layer in Photoshop, so the devs could then plop it in Unity. Didn't seem like the most efficient way of doing it. Been dabbling with Flash and After Effects, just not sure which program I should sink more time into.
I use a combination of Spine (esotericsoftware.com/) and Photoshop. I create the art in photoshop but then the final animation in Spine. They have some great video tutorials on their site. Check them out.