Of course, there are hacks like Nameless FireRed Project and Theta Emerald EX, but NES roms they don’t have any changes story-wise. You’re saying saving in one game will delete the previous game’s save file? Improvement type hacks (that don’t change the story) are on this list.
For example, this is how all the hacks tagged with FireRed look- link. There aren’t many complete hacks with mega evolutions.
If I knew of any other hacks, I would have already added them here. There are a lot of improvement type hacks (ones that don’t change the story but add features) which aren’t here.
Normally, I wait for Pokecommunity to accept a hack since they do a quality check, but since it’s your first hack and I had some time, I’ve made a page for it here. But honestly, what I do is easy; it’s the creators of all these ROM hacks that deserve all the credit.
You can check out Cloud White, Shiny Gold Sigma and Mega Power. Gaia has a few but they haven’t been implemented fully yet.
Stuff like Omega Red, Theta Emerald Renev, Nameless FireRed Project, etc. Please let me know if you’re aware of any complete hacks that aren’t on the list. Any chance could you do a hack based on team rainbow. I know of the hacks Rocket edition, The Darkest Timeline, Rocket Strike, Rocket Science and Apollo which are all amazing hacks.
I’ve kept this list free of improvement type hacks (the ones that don’t change the story) as I plan on making a separate list for them. Open world crystal hack, Kanto and Johto, 20+ choices for your starter. Gyms can be challenged in any order and the pokemon levels are adjusted accordingly to the sequence you hit the gym. The problem is, tagging doesn’t work great on Blogger.
Just thought it maybe something fresh for those Team Rocket fans like myself. P.S I would love to get into ROM hacking myself however lacking a PC at the moment great work keep it up. Any Pokémon GBA hack where we are playing as Team Rocket or other evil organisation apart from Pokémon Apollo. There’s already a page for it here, and it’s also on the main list.