1) World ownership
I do not want a world my sims live in to be a stage decoration. I need to be able to change it and decorate it. I want to decide which weather, terrain paint and deco are suitable for a world myself. Even this feature alone could make a gameplay much more versatile. Grunge or Victorian or Country or City this should be my preference. I need to have an opportunity to place my own lots and decide on their size.
2) Option to tweak and disable features.
Once again. I like to decide things in my game myself. Age, length of a season, presence of supernaturals etc. I want them all controllable! In Sims series each of games has some cons and pros in this department. I like how I can control some features (like aging of NPCs) in Sims4 but I absolutely hate that I only have preset options for age and length of season and can't set them myself. Or that I do not have control over supernaturals like in Sims 3.
3) More "generic" sandboxy approach to design.
Not sure how to formulate this in short... Let us design ourselves. Be it the most obvious Create a Style. Or other less obvious features. For example in sims 2 we had just Community Lot. No additional types, no building requirements and it worked! I didn't need a specific lot type for restaurant or shop or park, they all worked on a single lot type. And multipurpose lots were not an issue. Still can't have cafe and library both functional on one lot in Sims4 after 6 years... Or chats. I'm perfectly fine how in sims 2 "chat" is just a generic chat and accompanied by a meaningful thought bubbles and reactions it gives me pretty good idea on how it's going. I do not need multiple options for chat "about toys", "weather", "llamas" blah-blah-blah... Especially when they have almost zero variations in outcome. What's the purpose? Another good example is custom paintings like they were in TS2. You want a custom painting you put a jpeg in a folder and you have it.
4) No political correctness, please.
I do not need to be educated, schooled, lectured whatever. I remember I was unpleasantly surprised when I saw on twitter how SimGuruGrant (if I'm not mistaken) commented on a question about absence of more "adult" features like goose, "dancers" at the parties, robbers etc... He wrote something like "we decided not to risk a lawsuit"... Well guys, I have bad news for you. It's called self-censorship. And no matter which reasons are forcing it on you - weather it's forced by authorities in Authoriatarian countries like mine or by minorities in Democracies as they are now - this is not doing any good to anyone in the end. I hate cancel culture and hate to see its impact on media.
5) Not everything is butterflies and rainbows. Let things be bad.
Unfortunately I think only Sims 2 was good with Sims misery. The only thing I think I have against Sims 3 is that this feature was slowly reduced. And ended up nonexistent in Sims 4. Fears, job failure due to chance cards, aspiration failures were precious. And overall game should be harder - fires more deadly, food require mandatory ingredients, clothes shouldn't be free and so on... In the end as Tolstoy wrote "Happy families are all alike; every unhappy family is unhappy in its own way." )
6) Personality.
It's such a common place in all complaints now... What I mean when I say this. I do not want to decide every little thing for my sim, I do not want to imagine everything in my head and then act it out (in many cases with the help of poses and fake props). I want to decide in general on sim character and main features and see how it'll play out autonomously from there. Sim should be able to decide it's own attraction, interests, hobby, relationships with others and communicate all these back to me in the form of meaningful wants (and fears). Playing by sims wishes was a thing that many players were doing in the days of Sims 2/3. And it was really entertaining. That's what Carl is frequently talking about in his videos. Being in charge for every single plot twist and every single sim step is not always a good thing.
7) Integration.
With Sims 4 business model it's really hard to implement, but why this should be my problem? At least they try with expansions, but not always succeed. If you are adding expansive features make them workable backwards. Swimming - all water should be swimmable. Apartments - I should have them where I want them in my game. Toddlers - I still want to shop for toddler clothes... So on. If it'll lead to fewer DLC I'm fine with this since they'll be more fleshed out and well thought. The matter is will the publisher be ok with this?...
8) If we are playing with life can we please play with the whole life-cycle?
Each life-stage should be distinct, fleshed out and have value in it. Behavior, reactions, interests... all these should change during each life-state. There should be many interactions specific to age-group and between age groups. Children, teens and YAs won't behave all the same in same situations like chores, visiting different places etc... Also, you know, surprise, but children can do many things. They can ride bicycles, water plants, play many different instruments and so on... I feel like in Sims 4 children are a bit dumb... And in the end some minor but important features defining life stages like body hairs or teeth loss.
9) Real-life objects in life simulator, please.
I can deal without a gigantic microscope, cupcake machine, ball pit and weed vacuum, but where are my snooker, cars, strollers, bunk-beds, normal playground equipment I can have in my sims' backyard??? I can continue forever.
10) Bugs should be managed. In ideal world tested and ruled out BEFORE releases. And please do not pretend they are features.