I really wanted to post all of my achievements here... 🙂 until i realised that i didn't have that many... because most of the time i just spend irl money on limited time cosmetics..... and am slow at improving at the game itself.... not to mention i have a lot of... not positive... things happen involving bugs... but saying that i do have some positive accomplishments :D
I recently finished getting the last two bridges for placing along the front of my city!

The omega bridges, which are cheap to get compared to the other bridges, are in front of all the lanes where there are tall housing buildings 🙂 . I then have the plumbob bridge which is in front of the fancy deluxe plumbob park which is a very nice memory item because it was only given out to all players once, which is a good thing! the next bridge along the front of my city is the hope bridge which has nice lights (personally i voted for the more "Japanese styled" bridge but this stone bridge looks a lot nicer than i expected! I have hope that next year this years bridge becomes unavailable and is replaced by another bridge chosen in another vote! - (because i still want that other bridge to match tokyo buildings more :P)).
(I do also have some suspension bridges along the side of golf park just off the screen :D )
I also got the spaceship from contest of mayors which was my aim for this season! (i was so happy when i saw the coolest looking sci fi item, in the city league 🙂 because i am... unable to advance past there ever :P) It is really nice because of the big rotation animation that makes it stand out!
I am also proud of some of my old (now slightly rarer to see items... like the 2016 monument :P - its a shame i don't have any 2015 one because the game was less than a month old then... so there wasn't any special monument for it... ) having the halloween items from the first halloween event (the trees) feels like a good personal memory

This game never had anything wrong with the game itself.. i can accept that... although it definitely would be nicer if they removed problems like players using feeder cities creating unfairness by making upgrades from bubbles easier so there is less reason to use feeder cities! (or if they made them common enough they could be non-marketable... if there was a way to get rid of the excess ones....) i do believe the game is a great game though and i'm not complaining, just posting a positive suggestion to fix a problem 🙂 my city looks so nice, to me at least :P 🙂
Although you did post the title as a question... so i want to answer it 🙂 and i think the most "right" about this game is the fact the creators behind it all haven't given up! and new items and mechanics still come out to the game bringing more improvements for some player, somewhere, to enjoy! 🙂