This will be an honest and fair review, made by a die-hard Pokémon fan!
I've been playing a lot of Let's Go, and the game is simply amazing. "Everything" is revamped, making it more realistic like everybody wanted. It's more anime-like, it's cute, it's marvelous, it's epic!
Gameplay: this aspect is quite simple and easier. This game is meant to be a welcome sign to the new Pokémon fans that still need to learn a lot in terms of lore, mechanics, etc. Traveling, avoiding wild encounters, catching (like in Pokémon Go) is the easiest thing in the world and is very catchy for newcomers!
Soundtrack: this is by far my favourite aspect to review in this game. The soundtrack is simply amazing! You can stand in one place, close your eyes and listen to that certain theme music for hours! I always loved orchestral soundtracks and this one is no exception! If you feel that nostalgic vibe just like me, some tears of joy and happiness will drop down from your eyes, trust me.
Interaction with your Pikachu/Eevee: it's not annoying, it makes the game more realistic... and gosh, it makes you go "awwwwww" in less than one second! It's so immersive and makes every single event more memorable.
GO Park: this is a great feature, ONLY if you play a lot of Pokémon Go.
Sad points: pokémon can't hold items, no HM Fly, the online service is limited and there isn't a Safari Zone. I was hoping to see GO Park as an addition and not as substitute to Safari Zone.
Soon, this review will be bigger: I still have a lot to do in this game, but I'm looking forward to give more opinions when I'm finished. Hopefully, it will take a long time.