Gravity Field (Super Mario Galaxy)

Gravity Fields are special objects in the Super Mario Galaxy franchise. They make their first appearance in the first game, Super Mario Galaxy.

Description
As their name implies, Gravity Fields can control the gravity flow within their vicinity. This is hinted by arrows on the Gravity Fields's surface. These arrows often have their direction hinted at by a certain colour. Blue often goes down, though it goes up in the Battlerock Galaxy, while red often goes up, or down for the Battlerock Galaxy. Green often goes to the right. The other colours often go to the left. Blue and red are the most common.

Super Mario Galaxy
Gravity Fields are featured in the following areas:
 * Good Egg Galaxy: Gravity Fields make their first appearance during the second mission. When Mario enters the interior of the Pill Planet, he is subjected to blue and red Gravity Fields.
 * Battlerock Galaxy: Within the titular battlestation's gravity corridor, Gravity Fields appear, but their direction has been inverted, with blue going up and red going down. This is the only time this happens.
 * In Bowser's outposts and Galaxy Reactor, there are Gravity Fields, with their standard blue and red. The Dark Matter Plant's Gravity Fields nearly span the entire galaxy and are surrounded by Dark Matter colonies (This is the only time the green and other walls appear.). There is a short section of Gravity Fields behind the Galaxy Reactor's cosmic blocks. These are small and their area contains fire bars.

Super Mario Galaxy 2
Gravity Fields are featured in the following areas:
 * Rightside Down and Upside Dizzy Galaxies: Gravity Fields cover nearly the entire level. Their colours are blue for down, red for up, green for right, and purple for left. The green and purple ones make their only appearance near the end of the Breaking the Laws of Gravity stage in the former, while the ones in the latter's final segment alternate between blue and red.
 * Flipsville Galaxy: While the arrows within the background do telegraph the flow of gravity, they are not true Gravity Fields. Gravity Fields make their only appearance within a subterranean area after the Dirt Tower Planet. These alternate and their colours are blue (down), red (up), green (right), and white (left).
 * Battle Belt Galaxy: Gravity Fields appear inside the Undergrunt planet's core. However, their gravity is positive or negative. Their colours are blue for positive gravity and red for negative gravity. This is the only time curved Gravity Fields appear.