Played casually on my own at my own pace. Completion date is the date I hit the credits, but I'm still working on filling out the Pokedex (going for a living dex this gen).
!!Spoilers below!!
I LOVED the open world format!! Generally speaking I'm quite battle avoidant in Pokemon games, so I like going places without fighting things - the first thing I did after being set loose was to get to every Pokemon centre I could reach, and then discovered that defeating titans gave me more mobility, so I got far enough that I collected all the Pokemon centres while being only about 0-1 gyms in. And then I did the gyms out of order just based on whether I could beat the wild Pokemon outside the town. It was SO FUN. For the most part I did titans first, then some gyms, then the last titan, then finished off the gyms and Team Star bases in roughly recommended order.
I don't particularly like or hate the Terastal mechanic. It's...I guess...fun to pick up random Pokemon that have a wildly different Tera type...? I enjoy the trainer animations when they throw their Tera Orb though!!
Shinies not having an overworld sound/visual cue is definitely a downgrade from PLA, I hope that's something they might patch in in the future. I've found one (1) shiny so far, a Hoppip.
Character customisation - I do wish there was some kind of shirt/pants customisation but I really liked that the character creation styles are not genderlocked, and that picking the "girl" style doesn't make your character do pigeontoed cutesy poses (which is the main beef I still have with games that don't gender lock styles). I think for the first time since ACNH I felt happy with picking the "girl" style - I don't mind any pronouns being used on me, but in a game where I HAVE to pick between the binary I prefer going with the girl option because it's weirder for me to be permanently perceived as a boy (but the girly postures outweigh this, so in a lot of games I just go with the boy option...). Gender is a mess...
Story
What I think is the REAL strength of this game (aside from how fun I think the open world gameplay is) is the characters and the story. In past gens Pokemon has attempted to write deeper stories that come to a moral conclusion, usually through the antagonist team, and it falls flat because they bring up an interesting idea and then fail to resolve it in a way that actually addresses the issue - see BW (one of my favourite gens), where they were going somewhere with "is it not, perhaps, cruel to capture and battle Pokemon" and concluded with "but they were evil so their opinion doesn't matter!!" (This was meh on its own, but I could write an essay on why I HATED how they extended the story into B2W2)
Anyway. I was worried that would be the case here again, but there was a bigger focus on character relationships in this game, and it felt a lot more organic/more relatable than "random evil organisation does evil things". Yes, there's something bigger going on in the background - it really only gets addressed AFTER you defeat the E4/top champion, though. (There are a few hints about this, like the one paradox titan, but the bulk of the story that pertains to the Tera mechanic takes place very late in the game in a fairly short period of time) The story takes its time to develop your relationships with the 3 main friends (Nemona, Arven, Penny) and makes you care about them before putting you on a large time-travelled lizard (which is the fourth friend, unusually for the cover legendary) with all of them. To me it sort of echoes back to what BW was trying to do: have you meet up with your rivals (plural) but use these to give you a little window into who they are, what their goals are, their struggles etc. that's more than the traditional "sometimes they show up and you have to battle them".
That's to say...I really didn't expect to get SO attached to Arven. I thought he was a rude kid at the beginning but he's got so much going at the same time and he's doing his best. I also really liked the interesting things they did with gender role subversion here - your dream team is 2 girls (a battle prodigy and a nerdy hacker team leader) and 1 boy (a chef) (and a genderless lizard). Speaking of: the most put-together characters in the E4 are a tiny girl child and...surprisingly...a masc woman! Pokemon has been pretty traditional character design-wise (there ARE some fruity outliers but very few in prominent parts of the mainline game stories) up until this point, so this gen has been full of pleasant surprises, and I'm also really happy that Rika is as popular as she is - I hope that's encouragement for Game Freak to pursue more diversity in character designs.
By the time you get to Area Zero, you should ideally have become very attached to the 3 friends and your big lizard, and the Area Zero section is SUCH a fun part...I loved the banter between the 3 characters who've thus far been separated by their discrete storylines and are only just now actually making friends with each other. The ways they bounce off each other are really interesting, too...particularly where Nemona initially comes across as the typical Pokemon rival (doesn't care what state you're in, just wants to battle) but in her interactions with Arven, seems to actually be intentionally written to have no personal space/just isn't very sensitive. Also, Penny is very...online. She's very relatable.
And the climax of Area Zero!! That's a masterpiece. The area design, the offputting glitchiness...loved it. I loved how Koraidon has always been sitting in your menu, at the bottom, unable to be selected as a party member...but everything came back to things that were mentioned right at the start of the story (there is indeed a passing comment by Sada saying that Koraidon's one of hers). The inability to use any Pokemon other than those registered to the professor's name, the realisation that this could only go one way, the UI for it...it all came together in such an emotional moment. It's CLEARLY railroading you towards a particular set of actions (you must bring out Koraidon, you must Terastallize it, you must use super effective Tera Blast to defeat the opponent that doesn't have a super effective move on you) but each part of the narrative has a logical reason for doing each of these actions (only Sada's Pokemon can be sent out, you are surrounded by so many Tera crystals, your Koraidon must assert dominance in a cathartic comeback). That's ludonarrative harmony, babey!!!!!
The backstory is surprisingly dark, with people (including the professor) having died offscreen to Pokemon attacks, Arven having to grapple with his parent's negligence and having to make peace with the creature that captured his parent's attention because guess what! It's now part of his friend group! But it's also not its fault! I talked about this with a friend, but it was surprisingly good that they didn't write a parent-child reconciliation in favour of the parent's feelings when the parent is clearly in the wrong here. Arven wishes he had a better relationship and wanted to be acknowledged, but also says no, you can't say that now, and decides to move on in his own direction completely separate from whatever his parent was doing. The professor did what the professor did, and the AI did their best to stop it - we feel for the AI's struggles as they are trapped in the lab to fulfill research that the original started, and understand that it's not the AI's will to resist, but this is entirely separate from the professor's treatment of their child.
After thinking about/discussing it with my friend, I feel like the story probably works better in Violet where the professor is pursuing research into future paradox Pokemon - it's more pertinent to the current state of things where we're continuously pursuing future tech with no regard to how all of that affects what we have now. I'm consoled by the fact that I got to stare at Sada's little fangies for this entire part, however (and also I'm very attached to Koraidon).
There's still a lot I haven't experienced yet, primarily where the teachers are concerned (got to drag myself to classes sometime), but on the whole - MAN that was an experience. It was such an adventure. I haven't enjoyed a Pokemon game like this in so long (I'm told Sun/Moon was on this level, but it just happens to be one of the games I didn't complete). This is definitely one of my favourite gens.
There are some issues, of course - besides the numerous glitches there's a ton of lag, and some loss of accessibility features between PLA and SV (shiny indicators). I would honestly be happy to have a much longer development cycle than have to deal with the problems of a less complete game. That's about it, though.
I'm hoping for maybe an expansion...the top right part of the map is a chunk of nothing, rather than just map filler, which kind of suggests that maybe there'll be something new in the future...so keeping my eye out for news. I'd love to have more story involving the friend group and the E4 (Rika).........