> Jesse/James, the Surfing Minigame and updated Pokemon locations all return from Yellow. In Viridian you get a special follower Pikachu (so you still get to choose a starter from the traditional three)
> The opposite gender character is a new secondary rival
> All of FireRed/LeafGreen's features return, including Sevii Islands
> Heart Forme Ho-Oh/Soul Forme Lugia event on Navel Rock
> Updated Kanto regional dex to include all of the Johto, Hoenn and Sinnoh Pokemon you could get there in HGSS; we've got 700+ pokemon now so the old Kanto dex just won't cut it
> Updated story events to more closely follow the Origins storyline (Lavender Town, Silph etc)
> A Battle Facility with a Gym Leader Castle, Rental Pokemon, and other Pokemon Stadium staples
> Lots of post-game content that ties in with GSC/HGSS kanto
> Soaring and DexNav
> Replace the gambling machines in the Game Corner with machines that play a simplified, graphically-enhanced version of the old Pokemon Pinball Red and Blue tables
> postgame "151 Episode" involving catching Mewtwo and taking a trip to faraway island
All of this, plus passive quality-of-play changes, like including berry trees, headbutt trees, seasons, times of day, weather, optional dive spots, and whatever else they've included in newer incarnations
If they're going to do Kanto again, it needs to be done so well that they can finally fucking leave it behind for good
