I feel as though most romhacks will stay close to the original content. Sometimes the original content infuriates me, the biggest offese being boring, multiple wild pokémon battles. So I'm thinking, would players be against:

* changing mechanic formulas such as exp. Or damage point systems
* revising type charts
* revising the fact that each pokémon can/must be captured
* revising existing moves or adding new moves
* changing type mechanics by revising STAB bonus and/or adding type-change held items to the game

Side note I can't implement any big changes myself because I don't know how to script.

Looking at what's possible with pokemon crown mechanics wise... and the features introduced in games such as Unbound and Inclement Emerald.
I think with decompilation I can finally learn and start making something 'new'.

- Why just focus on pokemon trainers? There's all kinds of other parts of the pokemon world with other types of trainers and NPCs that also have stories. ​
- New battle / capture / base interaction mechanics. If it fits with the story like with the pokemon rocket hacks, pokemon crown's battle and capture system.
- If using a traditional battle system, bringing it up to date with modern standards or even improving on them. If it's a competitive focused romhack, listen to the complaints of vgc players like wolfyvgc and fix them.
- If it's a romhack made for streamers. Implementing quality of life features for them, streamer based gamemodes like enforcing nuzlockes etc... A hook that can 'do stuff' on certain twitch events happening for instance, native hooks to output your current party to display them on stream (I know mgba has logging... perhaps use that as a base to start, just log out to a file?).
- Do away with the traditional boy/girl with fixed appearance thing and absolutely let the player play as someone old/young/genderless/or even a pokemon
- Change some base mechanics involving how 'different' pokemon can be. There's the palette changer patch for inclement emerald which kinda helps making pokemon feel more unique. Add in mechanics that expand on the IV/EV/nature/(insert new system) vibe to make it feel like your pokemon are truly trained to be one of a kind.

Just some top of mind thoughts.

probably different/new types.
one hack that do this greatly is pokemon sweet version.
its really fun to figure out what type is super effective against another, and for me, it kinda brings me back to being a kid and discovering pokemon types.

I mean, like someone else in the thread already stated, Pokemon Sweet Version is kinda the only rom hack I know of that basically changed up the entire type chart, and that rom hack is quite old.

Would be cool to see more type revisions, though I would assume that takes a lot of work.

Being able to kill villains who kill other people and aim to take over the world instead of just letting them go.

i'd like to see a hack that straight up takes a pokemon game and turns it into something else with similar mechanics. kind of like a reskin but maybe more involved. it kind of defeats the purpose of a pokemon romhack but i also really want to see what could be done using pokemon as a base. it's something i dream of making but i know it would take a billion years and it would never get finished
edit: now that i think about it i think a rom hack based on those "pukey-mon" parody cards would be pretty great

I'm currently working on a type chart that adds elements from Persona 3, and could eventually be implemented in a pokecrystal romhack.
It started with wanting to find a use to Normal attacks, the same way Pokemon Crystal Maeson turned the Normal type into Beast type and gave it weakness to Flying type, amongst other things.

Out of the many changes, all Normal, Fighting, Dragon, and Steel moves no longer are assigned this type, they instead received Slash, Strike and Pierce, and Flying is replaced by Wind. Wind is now super-effective against Fire, as it is the case in most Persona 3 battles. But I on the other hand, I didn't dare adding a type effectiveness between Ice and Electric types. I've also added a Light-type to match the Mudo and Hama skills from Persona 3... I kind of dig the idea to have them in Pokemon too, as TMs, with the same accuracy (around 30%), to replace the existing OHKO moves like Horn Drill. Also, STAB is removed.

On the defensive side, Flying type is now called Avian, Normal type is now called Mammal, Dragon goes by Mythical, Steel is now Mecha.

Incidentally, although I wanted Bug to be defensive-only (in the same logic as Mammal and Avian), I found the offensive side of Bug still makes sense (SE against Psychic, Grass and Dark), so I kept it.

I enjoy a lot the idea of having defensive-only types and offensive-only types.

In the current form of the work, it seems like it would be hell to balance it out for the roster of available Pokémons and moves in pokecrystal, because 70% of my Normal-types moves have turned into Strike-type moves, and this type has at least 3 or 4 super-effectivenesses. I would have to change the whole engine to make it both interesting and balanced.

here's another random idea i had but i like the idea of being able to use items directly on opposing pokemon, similar to how you get to lob rocks and food at the poor pokemon in the safari zone and wherever pokemon snap takes place. maybe certain items would have certain effects that could be detrimental or helpful, or maybe scare off pokemon that would be too dangerous to try to fight? i dunno