Farm Hero Saga: What triggers 2 stars on rancid level?

Toobusy

Farm Hero Sage, how do you get 2 stars on a rancid level?   Do you need to get to a certain points amount?   It can't be from having left over moves because it ends the game as soon as you hit zero on the meter.   There is nothing on the meter to show how close you are to getting 2 stars like on a regular level.  

aCe

I noticed that as well, there's nothing on the pre-level screen. I guess you need to get a certain score but theres nothing to say what it is. I'm happy if I get 1 star and defeat the little rascal, haha.