At the iTunes store, it's described like this:
This unfortunate girl has so much extra weight that no diet can help her. In our clinic she can go through a surgery called liposuction that will make her slim and beautiful. We'll need to make small cuts on problem areas and suck out the extra fat. Will you operate her, doctor?
The developer, Corina Rodriguez, is behind a range of cartoonish and oddly medicalized Apps apparently aimed at girls, such as "Barbie Dentist & Barbie Dress up" and "Leg & Foot Surgery & Doctor & Hospital Office for Barbie".
@everydaysexism is currently trying to organize a Twitter protest to have the game, which is marketed to age 9 and up, removed from iTunes.
In the interest of pseudojournalism, I downloaded the free App and played it for as long as I could stomach (pun intended). As expected, it mostly delivers a barrage of pop up ads. But in between, and scored by awful stock music, you are actually taken through the steps of a cartoon liposuction using a manual bicycle pump: