So I've been playing fantasian and hot damn it has the best feature than any JRPG needs ,they call it dimengeon ,it's basically collects all your random battles into one battle that you can play it whenever you want ,it get harder obviously but the fact that you don't get interrupted while exploring is a bliss
1. Etrian Odyssey levels of character customisation where you can pick the look, the skin color, hair color, eye color, voice, skill sets. Here's a site that simulates it
A character editor for the Etrian Odyssey Origins collection
etrian-character-customizer.vercel.app
2. stylised pause screens like Goldeneye and Persona (I'm crying why are there no pictures of the pause screen from PSX Persona 1, it looked like this fan remake but was not as sophisticated ofc)
3. Pause screen music like Battletoads and Shin Megami Tensei V
4. A way to track when you'll encounter an enemy seen in 7th Saga/Mystic Ark, numerous SMT games and Etrian Odyssey
5. In game arranged music like a lot of ports for SHMUPs did. Examples include Border Down Dreamcast (that's where the famous harmonica cat song comes from), Mars Matrix Dreamcast (the Stage 1 song has a unique remix as a menu theme), Castlevania Chronicles (you can play every version of the X68K music on there, it's incredible), Pokemon HGSS (old music is unlocked when you beat the game), Persona 2 PSP, etc. It hate how many games just go one or the other so much.
Armed Satellite Phobos (Stage 1 Original)
Armed Satellite Phobos Fumio Remix (Menu Theme Dreamcast)
6. Side modes in fighting games, I talked about a while ago about how I wish fighting games have side modes as there is nothing to do in them save fringe examples like Blazblue and the hotly debated fighting game Smash
7. Unique banners for old game collections if you won't get widescreen. Dodonpachi Resurrection and Mega Man Legacy Collection have that down PAT
8. Class changing, like subclasses in Etrian Odyssey or just being able to change your role anytime like in the GOAT Final Fantasy V
9. Free/cheap healing. The ramping costs limit what you can do in games like Etrian Odyssey and SMT, though granted in the latter it's a lot easier to get Macca, but in SMT V that shit's a nightmare if you want to fuse
10. Different random battle themes. And I don't just mean Battle/Mini Boss/Boss/Battle 2/Final Boss, no I mean I want them to go batshit insane with all the different themes you can hear in game. Yakuza, Kingdom Hearts, SMT IV, SMT V, Mother 3, I want multiple different battle themes I can hear, I don't want to hear the same one all game (most of the time). A Lone Prayer, Mass Destruction, Reach Out To The Truth, Last Surprise, etc are all fine and dandy but they drive me insane with how often I hear them. SMT realised this ages ago and I don't understand why Persona didn't get the memo.
11. A ranking system, bonus points if you get awards. I don't want Sonic to be the only current franchise to do that
12 de-levelling to make the game harder like TWEWY
13 if you're going up against an over levelled boss, the game should give you a prompt and an option to temporarily put you on the same level as the boss while keeping your stats, moves and stuff so that you don't need to grind
14 more rhythm/rpg hybrids
15 more shmup/rpg hybrids
16 more games that use Persona 2's unique battle system
17. Last but not least, instead of locking the sound test to beating the game, simply hearing a song in game should be enough to listen to it in your own time. I forget which games actually did this, but I know what DIDN'T.