I'm working on a 2D game which involves firing projectiles around a solar system and having the path of the projectile change based on the gravitational pull of solar bodies.
I've been trying to find an explanation for how orbital mechanics work, at least in this simplified 2D scenario, but so far haven't found anything other than theoretical high-math documents.
I know that there are some existing games that do this already in 3D space, namely Planetary Annihilation and Interplanetary, but I haven't been able to find any references to how they did it. The Planetary Annihilation devs did a livestream demo of it once, but I haven't been able to find it since, and I don't think it went into much detail.
Whether by explanation or reference, does anyone know how 2D orbital mechanics work for the purpose of a game? How or where can I learn this?