Thanks for the feedback. :)
Yeah, that's definitely something I would love to address, but I struggled a lot with the math, and had to apply some workarounds. Eg. when the ball leaves the gravity of one planet and enters the next, it keeps the same rotation, meaning it will sometimes abruptly take a quick turn mid-flight. The temporary fix is to increase gravity by a lot, so that it dead drops onto the surface of the next planet.
I also want to disable gravity on the player character when they jump into space, and replace jumps with rocket boosts, which can only be used a few times before you need to land on a planet to replenish fuel. That would force me to add checkpoints/restart mechanics though, and rebounds/"wrap around the corner" when the player character leaves the game screen. Currently it's not an issue, since there's always gravity from the closest planet, which I'll probably keep for the ball.