Mr. Accretion Jr.

Mr. Accretion Jr. is a gun that fires planets. If a planet hits a wall or obstacle, it starts orbiting the player.

The gun has eight different projectiles resembling planets of the Solar System.

Bugs

 * works with black holes generated by the Black Hole Gun too, despite not being part of the synergy. May or may not actually be a bug.

Trivia

 * Firing or reloading Mr. Accretion Jr. releases a gas with a space texture. This effect is purely visual.
 * The description is a joke about the fact that the Gungeon is located on the planet Gunymede in an unknown galaxy, so its inhabitants don't know about our solar system.
 * The description is also a joke about the Flat Earth Theory, stating that the planets are flat and only appear as if they were spherical.
 * It's also a joke about the game itself, since everything in Enter the Gungeon (like all computer games with 3D graphics) is two-dimensional but exploits perspective to appear three-dimensional.
 * "Music of the Spheres" refers to a long-standing ancient mathematical concept which relates the rotation of the heavenly bodies to various mathematical proportions, as well as the pitch of a string to its size. The phrase, and concept, was popularized in philosophy by Pythagoras, and later Plato.
 * "Accretion" refers to the process that forms planets out of stellar dust.
 * An Orrery is a mechanical model of the Solar System that illustrates the relative positions of the planets and their moons. This name comes from the resemblance the player has when surrounded by orbiting planets, each of which is being orbited by its own bullet-moon.