Created by StupidMarioBros1Fan with help from Graslu00, Carnivorous and Sogun.

Tested on Carnivorous' 1964 60FPS Build and CEN64 and real hardware.

Installation:

Use the GoldenEye Setup Editor or XDelta UI and apply the proper XDelta file to a clean GoldenEye 007 (NTSC-U) ROM
Download XDelta UI - web.archive.org/web/20170523022132/files.catbox.moe/immoym.zip
Download the GESetup Editor - goldeneyevault.com/viewfile.php?id=37

Description:

This mod replaces all of the characters with ones from the Mario universe along with edited dialog to make more sense with the characters. For example there is no mention of Trevelyan/Luigi's parents being Lienz Cossacks and instead of calling James Bond/Mario the "Golden Boy" he says the "Golden Bro." Other changes include the dialog where Mario meets Natayla/Peach as Mario doesn't straight up say he's a spy to her.
The Briefing is edited to not only replace the names, but also with slightly different text. Not much, but there are small differences. Moneypenny/GoldCoin however actually has some different dialog such as mentioning that there is a girl in the cell next to you for Bunker 2. However the story itself is mainly the same as the original, with all Levels playing out basically the same as the original. There's small differences but for the most part it's just bug fixes with nothing majorally different to the levels....besides Train because characters are different sizes compared to the original but it functions the same as the original.

Characters:
James Bond -> Mario
Natayla Simonova -> Peach
Alec Trevelyan -> Luigi
Xenia Onnatop -> Daisy
Arkady Ourumov -> Bowser
Boris Grishenko -> Yoshi
Dimitri Mishkin -> Donkey Kong
Valentin Zukovsky -> Wario
May Day -> Pauline
Oddjob -> Toad
Jaws -> Waluigi
Baron Samedi -> Rainbow Bowser, the Powered-Up version of Bowser from Super Mario 64.
Soldiers/Civilians/Scients -> Koopa Troopas
Heads are now different expressions to make use of the Random Head system, hats/helmets are replaced with tiny models & Bounding Boxes of 0 because they would get hit first despite being inside the head. Thought about making them sunglasses, but it'd still get hit first before the back of the head did and overall was unfairly annoying.
Mishkin/Donkey Kong is no longer the Defense Minister, that role now goes to May Day/Pauline with Donkey Kong being the Head of Special Forces. This was done to give Pauline a role in the story, as well as explain why the "Great Guards" use DK's body.
Dr Doak is now Oddjob/Toad to give him some sort of role in the story, as a result the idea of Toad "blending in" with the other scientists is ridiculous.

Credits:

Custom/Edited Models by StupidMarioBros1Fan
Models imported into game by StupidMarioBros1Fan
How Tall & How Far Above Ground by StupidMarioBros1Fan
Bounding Boxes by Graslu00 & StupidMarioBros1Fan
Custom POV for Single Player by Carnivorous
Custom POV for Mulitplayer by StupidMarioBros1Fan
Animation Edits by StupidMarioBros1Fan
Custom Portrait Pictures by StupidMarioBros1Fan
Lighting Fixes for First-Person Models by Carnivorous
Rendering Fixes by Carnivorous
Level & Text Edits by StupidMarioBros1Fan
Testing on Actual Hardware by Graslu00
Peach's Castle, Bob-omb Battlefield & Big Boo's Haunt ported to rom by StupidMarioBros1Fan

HUGE Thanks to:

Graslu for Help, Testing and Advice
Carnivorous for Help and Advice
Sogun for the Multiplayer Maps and Advice
SubDrag, Zoinkity, Wreck, Trevor, 00action & others for the GoldenEye Setup Editor 

Links:

GoldenEyeVault.com - for more GoldenEye 007 & Perfect Dark mods
YouTube.com/StupidMarioBros1Fan - My YouTube channel for mods of multiple games
YouTube.com/Graslu00 - Graslu00's channel for videos on various GE007 & PD mods

Notes:

The gameplay demos that play at the end of the Startup sequence are kind of broken as a result of Mario's POV being lower, actual gameplay is fine.
As a result of most characters being sized to 2.0 instead of 1.0 (allows the guns to look bigger in their hands) a lot of characters run slowly in Single Player. This mainly means that Koopa Troopas take forever to run to places like Alarms, and won't sneak up on you as quick. Peach is sized at 1.0 so she moves at the same speed as Natayla, don't have to worry about her being slower. Toad is horribly slow thankfully though his only role in Single Player is to give you the Door Decoder in Facility which does not require walking on his part. Multiplayer is completely fine, all characters move at normal speed due to being controlled by players.
Train on 00 Agent is tricker to complete due to Bowser being so big, but it is beatable as both Graslu00 and I have done it on Console and Emulator respectively.
Luigi doesn't run around the ladder at the bottom of Cradle anymore, instead he just runs a little to the left. This changed because as a result of the slower speed, he liked to unintentionally run into the ladder which resulted in him flying straight to the top of it. This would make the level almost impossible without full health because he'd constantly shoot at you while climbing up the ladder...and that was on Agent. Needless to say, the fight isn't luck-based anymore.
For Multiplayer: Bowser, Rainbow Bowser & 2 Female Koopa Troopas are the most "expensive" characters to use as when combined, they use a lot of textures & just have a lot of triangles in general. While they don't crash the game, don't be surprised if they slow the game down especially if the map itself uses a lot of textures too.