Yes, this isn't me announcing I'm making a Phantasy Star III remake (Although I am SERIOUSLY considering it) this is me saying what would be required in remaking Phantasy Star III...
For starters, the generation system needs to go... Why? Because no matter what routes you take, and no matter who you marry, you will end up doing the same things (or exploring the same dungeons) anyway... Nial's entire quest is done in the 3rd generation, and obtaining Laya is even done twice if you married Lena, for whatever absurd reason you'd do that.
So, how do you eliminate the generation system, yet keep the story intact? That's extremely easy... Base it off Orakio and Laya back when the ships were still new. It'd tie easier into the Phantasy Star series if you were to do that, anyway...
Keep all the dungeons, all the towns, all the castles... Everything is fine as it is... Eliminate Laya's pendant until literally the end, and put the removed dungeons you can never enter back into the game...
Towns need to be remade to be more lively, maybe use different instruments for the same town music in different places... The towns themselves, have more going on, ppl talking about more, and houses not to plain and boring.
Use PS4 graphics for the sprites, and redo the coloring, for the tiles, PS3 doesn't have bad one's, if you just slightly edit them, and livin them up a bit with color... You could always use PS4 tiles, or even new one's completely...
Play as Orakio, traveling with Miun and Siren... Make Wren and Mieu parts of the ending after sealing dark force and hearing of his return in 1,000 years... Battle against Lune and Laya, with Laya joining at the end once she realizes there are more troublesome manners than just Orakio and his band of cyborgs... Wanna put diversity back in? You can switch between Orakio and Laya during the game.
These are just some ideas I had while pondering making my own PS3 remake, which again, I am not announcing, however, anyone considering making one, should take the whole Orakio/Laya war into consideration... You can keep the game almost the same, with a totally new story, and tie it into the Phantasy Star series in the process... I dunno, just kinda think it's a really good idea.