Pokemon Sparkling Red

Pokémon Sparkling Red is an in-development ROM hack of Pokémon Fire Red, focusing on shiny Pokémon.

With over 350 custom shinies and drastically increased shiny odds, your Pokémon adventure will be filled with shiny Pokémon. The ROM features a light overhaul of the Kanto region, offering a refreshing experience for anyone who has already played Pokémon FireRed or a perfect start for newcomers.

Pokemon Sparkling Red Edition includes all the content from the base game, along with additional features and adjustments to discover along your journey. It has a moderate difficulty level, with some slightly tougher battles than the base game, but nothing extremely challenging.

Features
Over 350 new shiny Pokémon for those originally found in the Kanto, Johto, and Hoenn regions.
Every non-legendary Pokémon from the Generation 3 National Dex is obtainable before the Elite Four.
Increased shiny odds (1/8 chance) to allow the discovery of many new shinies on your journey.
All trade and friendship evolutions have been replaced with other criteria.
EXP grinding areas in each gym town to reduce tedious leveling.
Reworked Poké Marts to sell many more items, such as evolution items and more.
Post-game content featuring encounters with every legendary and mythical Pokémon from Kanto, Johto, and Hoenn.
All new gym leaders, Elite Four members, and teams.
A brand new rival who uses non-Kantonian Pokémon.
Reworked routes, trainers, and Pokémon encounters across the entire region.
The ability to obtain multiple starter Pokémon throughout the game (at a rare encounter chance).
Better level balance and level scaling throughout the game.
Zero shiny locks for any Pokémon.
New areas that feature Pokémon not originally found in pre-Elite Four FireRed.
Reworked TMs and HMs to be compatible with more Pokémon.
And many more additional features for you to discover.

Source: TheGamesDB