I did the programming, the UI programming+design (menu), some art editing and some of the original game design!
I did all the art.
I did the art for all elements (except for the spring) and did the coding for asteroid orbiting and interaction with gravity.
I did all the 2D art (except for credits) and the concept art for all characters.
I did the concept art, lineart, and color palettes for all characters. Additionally I did some script editing as well.