As the beginning of a new Pokémon generation, you'd expect some big changes to shake up the gameplay. Otherwise what are we paying the developers for, besides a bunch of new critters to catch and a shinier coat of paint? Here's a list of all the notable changes, as well as new features or improvements.
1. The Wild Area
If you speak to some Pokémon fans, there's a good chance one of their biggest wants for the franchise--other than it becoming a fully fledged MMO--is for the games to be open world. In other words, you can freely explore the region, free of most boundaries, and be able to tackle quests in pretty much any order. In reality, that's probably going to take a long, long time to happen, if ever.
For now, the closest thing is the brand new "Wild Area". This is an extremely big area (by Pokémon standards, not open world standards!), located in the heartland of Galar, which you can explore open world style. Within the Wild Area, there are lots and lots of Pokémon that you can catch. Also, the weather within each individual zone can vary, affecting the Pokémon you encounter.
2. The Dynamax Factor
Pokémon X and Y introduced Mega Evolutions, which allowed certain Pokémon to transform mid-battle, amplifying their strength. Then Sun and Moon added Z-Moves, extremely powerful moves that Pokémon could use, but only once per fight. Unsurprisingly, Sword and Shield has its own battle gimmick: Dynamax, where Pokémon spectacularly increase in size.
Dynamax is only possible in certain places, like in the middle of Gym Stadiums or Max Raid Battles (basically, where there's space). When a Pokémon Dynamaxes, their HP will be boosted and all of their moves will become powerful Max Moves--akin to Z-Moves, but with potent secondary effects (like changing the weather!). Dynamax lasts for 3 turns and you may only Dynamax once per fight.
3. Max Raid Battles
When exploring the Wild Area, you're bound to come across some peculiar rock structures, possibly with a beam of light coming from within. These are Pokémon Dens, where you can participate in new Max Raid Battles. They're sort of similar in concept to raids in Pokémon Go. Unlike raids in Go, a maximum of 4 players can raid at once; you can raid locally or online.
During a Max Raid Battle, you'll fight a powerful Dynamaxed Pokémon. This Pokémon will have a huge health bar and will create a protective barrier around itself when its health bar reaches certain thresholds. To even the odds, you can also Dynamax your Pokémon. Win and you'll have the chance to catch the Dynamaxed Pokémon. These Pokémon may have better stats or rarer abilities than normal.
4. Pokémon Camp
This is Sword and Shield's version of "Pokémon-Amie" from X and Y or "Pokémon Refresh" from Sun and Moon. At virtually any point during your adventure, you can set up camp. When this happens, your party Pokémon will relax at the campsite and you may interact with them, to improve their affection, or just to have fun! Who's a cute Yamper? Yes, you are...
Additionally, it wouldn't be a proper camping trip if you couldn't cook up a meal. In the Galar region, the meal of choice is curry. You can create unique curry recipes by choosing certain ingredients and berries, found in the Wild Area etc. After choosing, you'll play a cooking mini-game, where you have to fan the fire, stir the curry pot and then inject the curry with love! We're not making this up!
5. Galarian Forms
Is this really a new feature, when Sun and Moon introduced Alolan Forms? Which are new versions of older Pokémon, with new appearances, types and abilities in order to adapt to the Alola region. Well, it's still something you should know about! Basically, Galarian Forms are the same deal as Alolan Forms, but these Pokémon have adapted to the Galar region instead.
We'll try not to spoil too much, so here are some early examples of new Galarian Forms! Galarian Zigzagoon and Linoone are Normal and Dark-types, instead of just Normal-type. OK, nothing too outlandish, since we had Alolan Rattata that played a similar role. But here's something new: Galarian Linoone is able to evolve into a brand new Pokémon called Obstagoon!
6. Poké Jobs
In the Galar region, companies love hiring Pokémon to take on part-time jobs, branded as "Poké Jobs". You can access Poké Job postings via the PC at any Pokémon Centre. Pokémon sent on Poké Jobs can earn experience points (or, later on, even EVs) without you having to lift a finger; the longer you send them out, the more points they'll earn.
This is essentially Sword and Shield's replacement for Poké Pelago, where your unused Pokémon can do something instead of sitting neglected in your Boxes. That said, don't you think this is dangerously close to forcing your Pokémon into slave labour? Of course, this is just a game, but something about this feels slightly off...
7. League Cards
We have a feeling that trainer customisation options are extremely popular with players. Like X/Y and Sun/Moon, you can change your trainer's look and outfit. But there's a new layer, in the form of League Cards. These are trading cards that you can collect, featuring pictures of your trainer, other player's trainers or even NPC trainers from the main story.
You can customise your League Card at any PC. First, you can choose a background, border and/or effect. Then you can select a pose and expression for your trainer, as well as move/zoom/rotate the camera. If you messed around with the Alola Photo Club, you'll be right at home. Finally, you can even select the texture for the card! Afterwards, you can swap League Cards with other players locally or online.
8. Quality of Life Improvements
Last, but certainly not least, here are some notable minor changes, which--although small, as a whole--vastly improve the gameplay experience! Once you enter the Wild Area, you'll have the option to access your Pokémon Boxes from nearly everywhere. This lets you change your party much more easily, especially after you've just caught a new Pokémon.
When leaving Pokémon of the same species in the Daycare Centre, the two Pokémon may share Egg Moves that they know (these are certain moves that are exclusively obtained via breeding). After completing the main story, you can purchase Mints from the Battle Tower that alter the increased and decreased stats because of a Pokémon's Nature. Both are game-changers for competitive players!