It’s another Pokémon game, and yes, it’s very much like all the others. In fact, it’s probably more like the slightly older games, like X and Y, rather than Sun and Moon as it returns to the gym setup those games had and Sun/Moon ditched.
What is different, is that there’s a new Wild Area, er, area. This massive (for a pokémon game) part of the map is full of wild pokémon which change depending on where in the area you are, and the current weather. There are also dens here and there with giant pokémon in them which you can battle and catch not completely unlike the raids in Pokémon Go.
The other difference, is that it’s the first mainline game in the series to not include all the previous pokémon in the Pokédex. I don’t know how many are missing, but there are still hundreds available plus all the new ones that have been added. Frankly, I don’t really care but I know there are grown adults on the internet who have taken offence to this because it’s the internet.
I’d seen that the game was very short, with some people completing it on launch day in under 8 hours. So imagine my surprise when I got to the game’s credits after just 51 hours. And I’d not spent forever training pokémon or “catching them all” or anything like that. Sure, I didn’t just stick to the story, but then why would you? Plus there’s a new story that opens up after you’ve finished the game, although I don’t know how long that is yet, I admit.
The important thing is that I really enjoyed the game, like the new quality of life features (you can now swap pokémon in and out of your box pretty anywhere, for example), and the “Britain but not” Galar region setting is funny. Other than that, it’s more pokémon, with nothing to really change your mind either way if you’re a fan of the games or not.