This is a really fun concept and a great foundation for a really awesome game! I loved the mechanics of moving around the planet using the gun. Initially I actually thought that I would "fall off" the planet if I went too far to each of the sides, but it makes more sense that the gravity pulls me towards it. If you added sound effects, particles and maybe even an upgrade system, I think this would be great fun :-D Well done, I hope you've had an awesome jam!