It certainly has aged but I disagree that it is out of date, I think it holds up well on many fronts.
That's the massive upside of 2D art. Quality 2D ages well and hardly ever goes out of date. The early cartoons will soon be a century old and yet one can still watch them without issues, while others like Bugs Bunny or Tom&Jerry are indeed still actually popular, despite being up to ~80 years old.
This game seems to be suffering from feature creep. Would explain why it's taken like what, 5 or 6 years to get to this point?
Feature creep describes it quite well, though I'd say that quite a few of them are actually welcome.
At the start the game could have been summed up like follows:
- mostly simple art with simple shading, which was just about good enought to be acceptable quality wise (not talking about character designs, as these can be argued about) - including some actual inconsistencies.
- 2 frame "animations"
- no/hardly any cut scenes
- no pregnacy
- very simple/repeatable quests to save dev time, like "earn money -> buy item x -> hand it over -> repeat" or even just "handing over money->done".
Now all of that changed, which, given that everything is drawn by hand, simply takes time. I'm not saying that DC couldn't have done things better - especially with the main story and the tech update - but it's not like there isn't a lot of content to show.
Then again, it's not like it matters that much. As mentioned above, the game is going to age well and a few years more or less ultimately won't really matter.