G-Mode

G-Mode, also known as Grey Mode or God Mode, is a trick that uses a combination of X-Ray Scope and a Reserve Tank in order to execute certain glitches.

Description

From the text at TASVideos:

Discovered by EternisedDragon in 2015. Running out of energy during a door transition does not trigger the R-Tank's "Auto" feature before the next room is fully loaded. When the next room finishes loading, there is one frame of game play before the R-Tank activates.

This frame can be used to activate X-Ray, and although doing so would normally cause the less-useful "R-Mode", found many years ago by Kejardon, G-Mode can be achieved instead if the input used for activating X-Ray is released within a ~3 frame window, while the R-Tank finishes refilling Samus's energy.

This enables control over Samus, but leaves some properties of X-Ray active - for example, the game is unable to execute any PLMs, such as crumble blocks or screen scroll controllers (which is the reason the camera doesn't follow Samus during this mode), meaning activating too many PLMs will cause the queue to fill up and make most of them nonsolid. Thus, through G-Mode, Lower Norfair is easily accessible through what is normally its exit by jumping through the nonsolid pillars and crumble blocks.

The mode is disabled whenever X-Ray is activated again, and since doors are also PLMs, they will not open while the mode is active (excluding the initial door, which stays open when the mode is first activated, allowing the mode to persist into the room you were originally in).

This method of entering Lower Norfair is viable for humans, although it does have you entering Lower Norfair at extremely low health, with the closest convenient refill being the e-tank in Lower Norfair Fireflea Room.

Other applications

G-Mode can also be used to cause save stations to execute a different PLM than normal, including giving Samus items. Once Samus steps onto the Save Station, it starts cycling through through the available PLMs. Once G-Mode is disabled by activating X-Ray again, it executes the currently-selected PLM.

The primary application of this so far is to get Gravity Suit by disabling G-Mode on a specific frame after landing on the save station, in the RBO Glitched category.