The optional Poké Ball Plus accessory for Pokémon: Let’s Go, Pikachu! and Pokémon: Let’s Go, Eevee! is a fun way to make your adventure more engaging, both on the Nintendo Switch and when you’re out and about, and the exclusive Mew included in each one makes it the only way to complete a full Pokédex. However, those who own the accessory should never delete their save file, as Mew will be lost for good if you do.
Nintendo mentions this on its support page, warning players that deleting your games save file will also result in Mew being lost forever. You can only transfer Mew into one game, presumably to prevent players from connecting their Poké Ball Plus to all of their friends’ games to give them all a Mew for free.
Mew can be found in the game by going to the “gifts” page, and after connecting to the internet, you’ll be rewarded with the rare Pokémon in your bag. Nintendo says that you can contact your local retailer if you can’t access Mew, but the character should be included on your Pokédex if you did so correctly. If you don’t transfer the Mew yourself, you should still be able to let another player take it.
You cannot fill out a complete Pokédex in either Pokémon: Let’s Go, Pikachu! or Pokémon: Let’s Go, Eevee! without the assistance of another player. Certain monsters like Meowth and Oddish are exclusive to one version of the game, and other monsters, such as Golem, can only be acquired after completing a trade and evolving them. This is no different than other handheld Pokémon games, which encouraged trading, but limiting Mew to one-time uses in the Poké Ball Plus is sure to make some fans upset.
Unfortunately, Let’s Go is one of the few games on Switch that doesn’t support cloud saving, so if your save is corrupted or your Switch breaks, you’re basically out of luck.
Mew aside, we are having an absolute blast in Pokémon: Let’s Go, which recreates the Pokémon Yellow story with gorgeous visuals, a simplified catching system, and classic combat. It’s one of the best games released for the Switch thus far, and it appeals to both longtime fans and younger players unfamiliar with Pokémon. Check out our beginner’s guide to help you get started on your adventure.