It just released late last year, and it is one of the finest puzzle games I've ever played. It took me around fifty hours to get the ending, and I've got a folder full of notes and screenshots from putting together puzzles.
Go in blind if you can, and do your best to avoid spoilers if you need to look up any puzzle solutions. This game has more depth than Outer Wilds.
Throw Void Stranger on that list. It's a fantastic Sokoban.
I specifically mentioned both Spyro and Ty because both series have remasters available on Steam. The Spyro: Reignited Trilogy in particular is phenomenal. They did a really good job making the updated graphics look just like my nostalgic memories of the game.
Psychonauts (the original, not the sequel, though the sequel is also good) is a Summer Camp themed 3D platformer. It doesn't quite meet your "low stakes/chill gameplay" criteria as it does have combat and mildly challenging boss fights and platforming, but it nails the rest. It's easier than Tunic. Maybe worth checking out.
Brothers: A Tale of Two Sons strictly meets all the criteria listed, but it's ultimately a tragic story. If "some kind of impact" includes leaving you in tears, check it out.
Okami is a Zelda style adventure set in feudal Japan with immaculate vibes. You play as the sun goddess Amaterasu in the form of a wolf bringing light and life to a land ravaged by demons. The world is cold and dark at first, but you bring spring and summer on your heels.
Finally, two favorites from my childhood are the Spyro series and the Ty the Tasmanian Tiger series. These are 3D Platformer collectathons and neither of these series are even close to any of the examples you provided, but they are bright and colorful and in my heart they have feelings of Summer Vacation and staying home all day to play video games.
I would flip my gender to female and ensure that my hair would match my Dad's hair color. Fix my chronic pain and IBS if I can, assuming those are genetic. Fix my singing voice. I ended up the shortest of my siblings, so double down on that and drop a few more inches off my height. I'm 5'8" now, so 5' even to 5'4" seem nice. My grandma's that height, so the code is in there somewhere.
Just Fireball.
When I chop onions I will just grab a few pieces to snack on raw while I cook the rest.
Edit: I completely missed the latter half of the OP.
I haven't done much experimentation. I know caffeine calms me down and helps "grease the wheels" in getting my brain to function. Alcohol helps ease my social anxiety and helps me relax and unmask around my close friends.
I haven't found any diet that specifically eases autism symptoms, but meal-prepping when I do have energy does help for the times when I don't.
Original off-topic post below./edit
When I'm not trying to lose weight I just cut sugary drinks out of my diet. My biggest rule is that if I go to the fridge for any reason I must pour myself a tall glass of water and drink that before I get to enjoy whatever snack/drink/meal I went to the fridge for. I don't drink enough water of my own accord, and this helps offset that.
I live alone, so I don't buy any food I don't have a plan to eat. I can't stand food just sitting uneaten. The recipes I've come up with for meals require simple fractions of products I know I can get at the store, so I can, for example, buy exactly enough ingredients to make my favorite stir fry recipe four times and have nothing left over.
When I do try to lose weight, I've found the keto diet has been most effective for me to actually stick to it and enjoy it. Even when I'm not strictly keto, I still stick to keto snacks and drinks, and just let carbs be in my meals. I have very little self-control around snacks that are in my house, but I have plenty of self-control at the store, so I just don't buy unhealthy snacks to have at home. Left to my own devices I can and will eat Girl Scout cookies by the sleeve and drink a 2-Liter of soda in one sitting. When my friends visit for board games and leave their snacks here they will be gone within 24 hours. The recent popularity of seltzer waters like La Croix have been a godsend for sating my soda addiction, since I can get the mouthfeel of soda without the carbs or the carcinogens in "diet" soda.
Skill based games aren't incremental. If you get your toolkit at the start and gameplay consists of learning how to use it effectively then
Examples would be platformers like Mario and old-school shooters before skill trees and gear unlocks became popular like the Halo trilogy. You're just as strong with access to the same tools at the beginning of the game as you are at the end.
A lot of modern "action" games have polluted this by incorporating unlocks and skill trees and other popular lite RPG elements, but incremental progression isn't "the basis of games", as you put. It's made an appearance in a lot of games because it's easy to implement and it's a consistent amd cheap dopamine hit to keep players playing, so it's very attractive to AAA studios looking for player retention.
Also not the point of this sub, as others have mentioned. This is for numbers go up games.
Farming? Really? Man of your talents?
That makes a lot more sense now. Thank you. I know where to look for troubleshooting next time I play.
Super Smash Bro's Ultimate is still the premier Couch ~~Co-Op~~ game for my circle of friends. We also play the JackBox party games and occasionally Mario Party.
I genuinely don't know what options are even available outside of Nintendo's fence anymore.
Edit: My reading comprehension is in the garbage today. Baldurs Gate 3 and It Takes Two.