You people have no idea what makes a good game. How about
>Regional Pokédex of around 250 Pokémon
>Game can have a story, but it's optional and not tied to the main progression of collecting badges
>You have 1-2 other characters that are relevant in the game, but they're on their own journeys and only occasionally come across you. One is kind of a competitive asshole (starter strong to yours) and the other is friendly (starter weak to yours). The latter doesn't need as much focus and should be the player character of the opposite gender.
>Locations with branching paths that lead to different cities or side areas, lots of dungeons featuring multiple paths with meaningful rewards.
>TONS of methods to encounter Pokémon (grass, surfing, caves, fishing, headbutt trees, honey trees, specific days/times/seasons/weather, SOS, hordes, Poké Radar, current music, swarms, having a specific game downloaded, etc.) each with a ton of exclusive encounters
>Game is paced so that if you battle every Trainer, by the time you beat the Pokémon League, you'll have completed the regional Pokédex
>Post-game unlocks National Pokédex and various encounter methods (Super Rod, Poke Radar) that make another 450 Pokémon available
>Post-game also has a bunch of new areas to explore (Battle Frontier should be there as an option for players into that sort of thing)
>Tons of post-game Legendary Pokémon with unique story events and locations like Heatran with Stark Mountain or Cresselia with Fullmoon Island
>Mythical Pokémon have story events and special locations like in Gen IV
>Following Pokémon is OPTIONAL
>No reusing the exact same battle music from previous games for Legendary Pokémon. Make new remixes
>Gym Leader rematches (something like the PWT would be nice)
>Friendly NPCs like the regional professor shouldn't be intrusive. Bring back the feeling that you're on YOUR journey, not that you're being watched over
>There shouldn't be tons of roadblocks
