I didn't enter so I can't rate, but here's some feedback.
It can be unclear at some times whether I've solved a puzzle or failed it, as both transitions are the same. This delays the feeling of satisfaction from beating a puzzle to after the fade completes. My suggestion for making this clearer is to have a correct solution fade the screen to white, and a failure fade to black. This would eliminate the wait to see if you'd succeeded, and allow you to immediately celebrate or prepare yourself to try again, respectively.
It can sometimes be difficult to see why exactly you failed a puzzle, due to the fact that your only visual feedback prior to the fade is that of an incorrectly matched orbit turning red. When a body has already been paired correctly, its orbit path disappears and will no longer turn red if another body begins orbiting it.
Sometimes it feels like the tractor beam is detecting a body between it and its target where that's not actually the case. This was most noticable in levels 15 and 16, where I could have a clear line of sight but the beam wouldn't activate. It seems like in some cases attempting to use the beam and failing will permenantly disable it.
Clicking on the home button or other menu while a transition is active can cause a soft-lock. In-game it can be cleared by pressing space, but at the main menu screen it put me in a state where I couldn't activate anything.
Overall I really liked it! I beat all the levels but 17, which I'm convinced is bugged (or maybe I'm just bad).