Check out Gravity Flipper here: http://www.ludumdare.com/compo/2014/08/26/gravity-flipper/

In this game you control two characters which are both trapped in different worlds. 

The only thing connecting the two worlds is you. 
You must keep both characters alive by reversing their gravity. 

Unfortunately, both of the worlds are connected. 
Reversing one world’s gravity will also reverse the others. 

Try it out now!