Nintendo has debuted gameplay of the upcoming Switch titles, Pokémon Let's Go Pikachu and Pokémon Let's Go Eevee, at their Nintendo Treehouse Live event during E3. Various gameplay elements were shown and certain features confirmed.
As mentioned during the announcement event, the games are based on Pokémon Yellow. The footage we saw showed the same progression as the original Game Boy games, though Viridian Forest to Pewter City and taking on the gym leader Brock. Wild battles have been replaced with a Pokémon GO-like system where Poké Balls are thrown. Berries can be given to the wild Pokémon to make it easier to catch. Trainer battles are the same as previous games.