Well, as a long-time player of the Pokemon series from gen 1 of the Gameboy Color to gen 8 of the Switch,

Certainly, it didn't come out as everyone expected.
It has its good and bad points.

Graphics
Let's start with the most well-known aspect that almost everyone looks at nowadays, it's not good. For a game on the Switch, I expected something better. They could have done a better job for sure. Essentially, they took the designs of the Pokemon from Sun and Moon and put them there as makeshift work. The trees look very bad, as does the ground. Definitely one of the downsides of the game when you're playing on a console, you expect something better than this.

Gameplay
Menu: quite easy and simple, easy menu

Story: you don't have one rival but 3, which makes it more interesting with nice battles. However, the main rival who talks a lot can be annoying at times, especially when you encounter him multiple times. The legendaries are interesting, especially Eternatus, which was the Pokemon that introduced the whole Dynamax to the Galar region.

Wild area: the wild area is quite beautiful to explore and you can catch 90% of the Pokemon there depending on the weather. You can spend endless hours there without realizing it, and you can catch Pokemon that already know egg moves. If you find a Pokemon shining with an aura around it, catch it.

Cities: all the locations with gyms and everything you pass through are very nice and require some exploration because they all have different items.

Battles: very nice. As a VGC player, I play more Doubles, which are faster and require better setup. As for Singles, they are slower due to stall Pokemon. The atmosphere is great, you can choose the theme you want to listen to while playing, and in some battles, you can hear the voices of the crowd cheering when you Dynamax. Pretty cool!

Trades: classic, but it seems a bit faster, although sometimes there is a wait for the trade to start when you select the Pokemon, it takes a little longer. There is also the surprise trade, basically a wonder trade where you choose a Pokemon you want to send and the system finds someone who wants to do the same and the trade happens. Very useful for completing the Pokedex.

Breed: you reach the first nursery very quickly after the first badge, and you can start immediately. It's much faster, and with a charm and a Flame Body Pokemon, it only takes a few seconds.

Max raids: the coolest element in the game. In the wild area, you find the so-called dens, which depending on the color of the beam, red is common and purple is rare. Depending on the Pokemon, some have more shields than others and it's quite difficult to bring them down at first. You can either join with online players, but you need to have friends on your Switch who are playing, otherwise, you won't find people. Alternatively, you can go offline and only play with bots, which will be much more difficult.

Dynamax/Gigantamax: it's really cool to see them become huge and powerful. The difference is that Gigantamax changes the appearance of the Pokemon and becomes more powerful, with different effects and moves.

Comms: The comms are when you want to connect online to find other players, it has many issues, sometimes it doesn't show your friend's raid if you have planned to play together and you need to log off the comms and log back in, and overall it is quite slow, I consider it the biggest problem in the game especially for those who play online.

Sound: The sound quality is quite good with nice music and clear.

Overall, it is very good but fast compared to other games and much easier, for those who have played the old games just know that it is very easy to finish the league, etc., for me, it definitely needed another year of work but it doesn't mean it's bad, on the contrary, it is very good, it just could have been much better.

Know that if you get any version of the game, you can find the exclusive Pokémon through trades with friends or online through the surprise trade, or if you search on Reddit, you will find some codes that give you exclusives from the other version.

And now they announced the DLC for €30, which is good because you don't need to buy another newer version like Ultra Sun to play the whole game again with minor changes... They will add 2 new wild areas and dens for raids, as well as legendary Pokémon raids!

I have played for about 12 hours, so I can make a first review.

Let's start with the POSITIVES:

1) Visually, it is by far the most beautiful game in the series to date.
2) They have simplified some things that were previously not possible or simply tedious (e.g. you can now change the nature of your Pokémon).
3) The Wild Area is an amazing concept that, with a little attention and development of the online and free roam aspects, can become a highlight of the series!
4) Quite nice new Pokémon (plus Galar versions of old ones).
5) The Gym Leaders return and gain a little more substance with the gym missions that precede them.
6) Character customization with plenty of stylistic options.

Now let's look at the NEGATIVES:

1) Visually, it may be the most beautiful game to date, but it doesn't fully exploit the capabilities of the Switch, as there are some rough edges here and there (trees, ground, etc.). The cities also need a little more life, although they are beautiful, they feel a bit empty. And finally, it's 2019, let us rotate the camera with the right joystick...
2) The GTS is missing and I don't understand why... What could be more convenient than saying "I'm looking for this" and someone else doing the trade if they're interested.
3) The infamous Dexit. Personally, it doesn't bother me at all because after years, I might try to complete the Pokédex again, but it is important to many.
4) The online aspect needs some work, especially in the wild area, where the fps drop quite a bit at times.
5) Dynamaxing is fun, but it's not anything amazing except maybe for max raids.
6) Simplistic story as usual.

Overall, it is a good first step for the Switch and the mark is definitely positive. On the other hand, they played it quite safe, as the console could definitely handle something more, and I think with the profits that this franchise brings, they should give it a little more care. It is worth it as a game, and anyone who is a fan of the series, I think will enjoy it.

Negatives:
They removed 400+ Pokémon, the graphics of the trees are like PS2, especially in the game they are tragically eye-catching, they only added 2 incredible legendary Pokémon, they removed the tragic elite four, they removed all mega evolutions along with the z moves, you can finish the single player in 20 hours, even less than Let's Go Eevee - Pikachu, and finally the starters are the worst starters they have designed in the history of the game. We are talking about a company worth 90 billion that simply makes stupid mistakes because they have become very lazy.

Positives:
They added max raid battles, they made it much easier and faster to create a very good competitive team, they added gigantamax which is very nice and brings a new freshness to the game, finally you don't need trades for many Pokémon that used to evolve only through trade like Gengar and Machamp, the music in the game is awesome, especially in the gyms, and finally it is one of the best Pokémon games I have played, the story is very good, they just have many mistakes and it's a shame because it could have been much better if they just listened to the fan base. However, it is a game that is worth its money even with the mistakes made by Game Freak.