2D Player attracted to Planets

I am trying to get a Player attracted to Planets with different Gravity, like Angry Birds Space or Super Mario Galaxy(if you imagine it in 2D). The Player should be standing with his feets on the Planet, that he automatically Rotates. I have searched for many different ways and tried them out or recoded them. If someone could help me out with a Script that allows a 2D Character to walk/jump on Planets, i would be very pleased.

Sorry if my English is a little bad, I am German.