We're all getting old, unfortunately.

Now there is certainly more to "moving characters", because using few sprites and just scaling and rotating them for movement quickly leads to the "puppeteer animation look"... which isn't too great either. There are tricks to avoid this too, but I feel that's enough writing for one thread.

So to summarize:
1. keep pixel sizes as consistent as possible, avoid strong scaling
2. rotations are not as bad
3. both scaling and rotation are ok when it's for moving/dynamic

And thus, my final rule: when it's moving, it's fine ok to scale and rotate. Players are less likely to notice.
Just make sure to not keep things too still.

This includes in particular: moving actors and effects.

And finally: people will notice a broken pixelart look when they take the time to look at it up-close.

For certain things, that's a lot harder to do:

Anything that's moving.

Which brings me to my second rule:

Rotated pixels are not nearly as bad as inconsistent pixel sizes.

Here are the wrong pixels:
left: rotated pixels
right: upscaled pixels
Which one did you spot first?

In my opinion/experience: you will notice upscaled pixels a lot quicker. Rotated pixels on the other hand... they are "easier to tolerate".

So, when using a higher resolution you can achieve zoom-ins that look cleaner. But the downside is: when rotating pixels, you will notice. Right...?
Let's do a little experiment:
Can you spot the "wrong pixels" in this screenshot?

And this in my opinion is the biggest take-away here:

To achieve a "clean pixelart look", pixelsize needs to be consistent. But they don't have to be perfect.

When neighbouring pixels have a x2 or x3 size difference, you will notice. But a size difference of +-50% can be tolerated.

So just reiterate:

In the pixelperfect zoom in, neighbouring pixel sizes switch between 1x1 and 2x2 pixels.
It doesn't look great.

In the x2 resolution zoom, pixel sizes switch between 2x2 and 3x3 pixels.
And it looks better.

Now, when using a higher resolution (say x2 the original) zooming in suddenly looks a lot "cleaner". The increased resolution allows each pixel to fall into a somewhat similar size, making their size more consistent.
It now looks arguably more "pixelperfect", even though it isn't.

For any zoom-level that leads to a clean multiple of the original pixelsize... you get inconsistent pixelsize. Especially when having fluid zoom-in and zoom-outs it can look jarring.

That didn't stop PlayStation games from just doing this, though.
So to some extend, it's authentic pixelart.

There are a few downsides to using a pixelperfect style. One example: zooming doesn't look too great. If I zoom into the previous screenshot it looks like this:

Just to clarify: with pixelperfect I mean that every pixel has exactly the same size. There are not upscaled pixels, no rotated pixels and so on.
Achieving a pixel-perfect style isn't all that hard: you simply render the game in low resolution and that's it.
Most old pixelart games look like this

So I've been working with pixelart ever since I started working on games (which is now over 20 years counting my RPG-Maker years) and over time I settled on a few rules on how to keep things "looking like clean pixelart" without the need to be pixelperfect.

This example features two things that break the pixelart look.
1. Pixel rotation
2. Different scales of pixels

In Alabaster Dawn, we do rotate pixels a lot for dynamic parts, but we avoid inconistent scales pretty thoroughly.