Pokémon Aquamarine

Intro:
Pokémon Aquamarine and its eight variants are ROM hacks of FireRed that takes place in Manta, an entirely new region based off South America. The player character mysteriously turns into a Mew, and takes on a journey as a Pokémon trainer to figure out how to turn back to human.

Each variant corresponds with a different Eevee evolution. The differences between versions are minor and mostly aesthetic, so it is recommended you go with your favorite!

These variations include:
Opal - Eevee
Aquamarine - Vaporeon
Topaz - Jolteon
Garnet - Flareon
Amethyst - Espeon
Onyx - Umbreon
Turquoise - Leafeon
Quartz - Glaceon
Zircon - Sylveon

Story:
Pokémon Aquamarine opens with the player character having a strange dream. A ghostly figure named Ilex claims that the player has turned into a Mew, and must embark on a journey to return to their human body. The player must be careful as Manta is home to Team Tactix, a group of dubious scientists who study Pokémon genetics. It is thought that the influx of Shiny Pokémon in Manta is due to their experiments. Could they be the ones responsible for turning the player into a Mew?

The game diverges whether the player chooses to play as a boy or a girl. As a boy, the player turns into a regular Mew. As a girl, the player turns into a Shiny Mew. The events of the game vary depending on this choice, similar to the version exclusive changes of the main series.

Features:

New Region based off South America
New Subregions based off Hawaii, Galapagos, and Antarctica
Sci-Fi story with a diverging plot depending on gender
All 411 species of Pokémon are obtainable without the need to trade
Certain Pokémon from newer regions up until Paldea will appear
Custom Fakemon include a hummingbird line, a dolphin line, and a tortoise line
Updated mechanics, including the Fairy Type and the Physical/Special Split
Updated Pokémon learnsets to include a more diverse set of moves
Newer gen moves with custom animations
Expanded bag storage
Dynamically changing Pokémarts based off number of badges
Items from newer games include Bottle Caps, Nature Mints, Ability Capsules, and Choice Items
TMs have infinite uses
HMs can be forgotten
HMs and certain TMs can be used by the player character Mew as field effects
AMs (Ability Machines) can be used by the player character Mew as field effects
Key Item that provides hints for next objective, suggests level caps, and spawns unlimited rare candies
Key Items that provide services such as EV/IV checking and Move Tutoring
Color-Coded Natures
Pokédex accurately shows Pokémon locations and stats
Quality of life changes from newer games
Decapitalized most in-game text