Although this Koikatsu Moémon Project is not affiliated with the Rom team in any way shape or form, the primary inspiration for these models comes directly from their work - so without them, there's no "us", so credit must be given and promotion of their work whenever possible. Besides, the games are great!
This new version has a ton of really awesome features, including lots of what Moémon FireRed version has to offer, but much, much more!
Check the official ReadMe for all of the features, but here's some highlights:
Over 800 Moémon species added, including some from Gens 8 & 9.
Mega Evolutions.
New locations, rivals, and other additional content.
30 Legendaries.
Day/Night cycle with new battle backgrounds and overworld graphics.
Reusable TMs and HMs turned into items, no more HM slaves! Goodbye, Zigzagoon! jk I still love you and you will be on my starting team for Pickup :P
Tons of more stuff, like optional difficulty increases, EV training, new Pokéballs, and more!
Now that I'm done shilling, go check it out yourselves from their official discord, or here at the link below!
https://forums.pokemmo.com/index.php?/topic/71562-moemon-star-emerald-and-mega-moemon-firered/
I'll be playing all night - er, after I finish up the next release of course! And by the way, the above screenshot/scene was thrown together in like half an hour, inspired by the intro screen for the game.

It's very simple, but I could upload the scene for anyone who wants it later!
Enjoy!