So, this is a fan made game made by a team of modders, it takes place 35 years before Red and Blue and you play as a young Oak or Agatha. I played the small demo which is all that has been released so far. But it was GREAT! The music, the graphics, the shadows, the new dialogues and the map! Give it a try, it's really easy to install and works perfect! And please tell me about what you thought. Pokemon Generation Zero (Yes, TsukasaKun reminded me of making this post...)
Not sure, they haven't decided yet. But it will be like 90% old Gen 1 Pokemons. Some (like Eevee) aren't going to exist since they didn't exist 35 earlier. There's a demo to download if you want to try it ^^