Great game here! Looks great, but I think maybe a planet's gravity field size could be more obvious? Maybe like circles around the planet just to give the player more of an idea on where the gravitational field reaches. I also think that you should limit the number of planets in each level. It takes a lot of time to tweak sizes when planets have a lot of different sizes, and so I would personally recommending removing the unnecessary planets just to make it a little bit less time consuming for the player. I spent ages on a level with like 5 different planets and even after 5/10 minutes of tweaking I didn't get it, so also a fast-forward button may help? Amazing work!