The concept of Pokemon fully realized and unhindered by the need to filter it so that its five year old friendly. And more importantly, it would be in 3d and combat would be realtime.
You'd start off being able to fully customize your character's appearance, then you'd start on the story and pick the starter pokemon that best fits your personality (and your starter choices would depend upon the area of the game you choose to live in, so you wouldn't be automatically restricted to Fire, grass, or water types from the start)
You be able to interact with your Pokemon kinda of similar to how you'd interact with your Chao in Sonic Adventure 2, except you'd also be able to speak with it, encourage it, play, etc. Basically you'd both verbal and non-verbal social interactions that go towards influencing your pokemons feelings towards you, as well as their personality traits (like niceness, laziness, arrogance, etc.)
Walking through the world you'd be able to interact with characters realtime through voice. Everyone would be different, and always has something to comment, and preferably these characters would incorporate an AI far more powerful than that which is currently seen in games today, that way you could build relationships with these characters, and make them your dearest friends or enemies with the words you say to them.
You could also infleunce them to join up with you, or become so popular they'd start a fanclub of you.
There wouldn't be an officer Jenny or Nurse Joy in every town and Pokemon Center.
t some point or another you could join up with any of the Teams in the game like Team Rocket, or Lance's group (whose name I forget), or just stick to being by yourself; An endless suply of quests and sidequests would be presented to you by NPC's or newspapers you might find.
Most importantly, the story and graphics style would be much darker and less 10 year oriented. We're talking about instilling all the ranges of emotion at varying levels, not just happiness at leveling up a prized pokemon, or annoyance at losing a battle.
The graphics would be gritty, as would the pokemon; they'd still be recognizable of course, but they'd be more real looking, with a stylistic flair to their proportions to also make them cool.
Pokemon would also be able to kill their opponents, depending upon how you've raised them and what your alignment/job is in the game (Team Rocket/Aqua/Magma, freelance trainer, or active good guy). If they're a gentle creature, then they wouldn't be able to perform a final blow, and forcing them to do so would damage their ability to fight and their relationship towards you. Alternatively if they a bloodthirsty monster hellbent on destruction they'd jump at the chance for killing another pokemon.
You'd be able to go on rampages Morrowind style; there'd be consquences to your actions of course, but that mentality of you against all of Pokemon-dom would rock ^.^;
Battles would take place in real time; using the aforementioned voice system to speak to npc's, you' be able to issue real time commands to your pokemon such as dodge, attack, defend, return, etc. Your pokemon's ability to react to your commands would be determined by how well you've trained them/their feelings towards you.
You'd be able to roam the entire game world (Kanto and Johto in this case), Morrowinds style. The only restrictions placed upon where you could go would be the dangers of your destination, and the strength/ability of you and your pokemon to deal with them. Obviously you wouldn't want head straight for Victory Road when you just started the game.
If I were to get this game, just hook me up to a liquid food dispenser, put a toilet beside my computer, and I'll never move again.
I just wish making it were within the realm of possiblity ;_;
Lol, longer than I'd planned. I've wanted to just get this off my chest forever >_>;