Level 1 is fairly simple: just get 3 planets to orbit - very elliptically - around the black hole. Cool: they can go in different directions.
Level 2 Get 5 planets around a black hole with greater mass.
Level 3 Get 3 planets to 'infinity orbit' (my term) around 2 black holes.
Level 4 Get 3 planets to orbit (somehow!) between 3 black holes. That's where I got stuck.
Orbit - Playing with Gravity is FREE.
If you solve level 4 and other levels, please take a screen shot and send them to me.
By the way, according to Stephen Hawking's book A Brief History of Time, time slows down for anybody riding a on a planet into a black hole.
Go to JE's site: http://genuss-gedaddel.tumblr.com/post/131157300406/orbit-ein-wenig-physik-f%C3%BCr-zwischendurch-gerne
He completed all of the puzzles and posted wonderful photos.