>Standard 2d overworld/map from Gen 1-6
>Standard battle rules, i.e. can only learn 4 moves, strengths/weaknesses for types, etc.
>On 3DS/Smartphone (For those who decry playing games on phones, let me remind you, Nintendo knows that people will download pokemon crap onto their phones)(also pokemon on phone isn't that bad cuz it's not actioney enough to warrant real buttons.)
>You can catch wild pokemon in the new region, but also go to gyms/marts/department stores/hospitals etc. in real life for in game bonuses. (Think Nintendo Zone specifically for pokemon)
>Game can be completed in full without going outside.
>No new pokemon, just what exists already, trimming trashmons as necessary.
>Can play multiplayer in the 2d world.
Here's the biggest point I wanna make, there would be a lot of research into the userbase of pokemon go. It would determine how IVs are generated. The better IV pokemon appear across all platforms of the game at a constant rate. It wouldn't be online only, but online functionality would play a large role.