You’re being sucked down a gravity well in Black Hole Joyrider, and there’s little you can do about it. Straying outside of it is much, much worse for your continued life, though, so you’ll need to carefully apply the brakes in order to guide yourself around the various loops and turns of the well.
Doesn’t sound so bad, except this isn’t a car, it’s a space ship. Braking requires use of reverse thrusters, which requires fuel, of which you have a limited supply. So, you’ll need to be sparing with those brakes to keep from running out of fuel for them, but also use them enough that you don’t send your ship into the crushing void. But her, at least you’ll have some nice Mozart to listen to while your body gets pulped by your pulverized ship!