Enjoyed it! Definitely needs a few things for the 5th star though - most notibly a 'Save' function!!
Other suggestions:
1) Shader/dithering overlay layer to add depth and shadows
2) A bit more variation on the color options
3) Ability to change color of symbol and accessories
4) Body-style options (Bulky, thin, tall, short)
5) Pose options (standing, hovering, crouching, etc.) (yes, I realize that exponentially increases artwork, but would still be very cool)
6) For the Save function - ability to save both/either final image and configuration (that could be reloaded).
Good app though! nice work.