Beautiful concept and presentation. I must confess that while I had a lot of fun with level 1, level 2 was a bit frustrating, and I was never able to catch the two fastest satellites on level 3.
I had a thought for an 'easy mode'. Maybe when the satellite your tracking goes outside your reticle, the progress can just start to decrease (at the same rate it increased) instead of going back to zero.
Either way, I really like the look and feel, even if it's a bit too hard for me.