As I'm sure a lot of us know, a lot of indie games tend to use the pixel art style for its games. Some people do it because it's easy to make (although they're wrong in some cases), others to give a sense of nostalgia. However, I see it quite often that a lot of games that are pixelly use a lot of transparency. Not necessarily anti-aliasing, but just various sprites and whatever having transparency on it which you couldn't see very often in games on 16 and 8 bit consoles (well maybe a little bit on 16 bit). Just so we're clear, I mean transparency as in a red with a 50% opacity, not simply a lack of color. I honestly feel like having that in your game sort of draws me away from it. What are y'alls thoughts on it? With the ever-growing amount of indie titles that use that style, I just feel like few of them use the style to their advantage (like Shovel knight did).

What are some examples from games where you see those mistakes? I ask because I'm not familiar with all the terminology and am trying to learn as much as I can.

I agree with you on just about all of those, especially rotating sprites (Although I can understand that it can be difficult to as I say "respect the grid" for games that use pixel art). By improper upscaling, are you referring to upscaling where the pixels aren't all in the same proportion to each other?

Ah. So using photoshop-y tools and brush art stuff in a pixel art setting?

More or less, yeah. Basically if you use modern graphic stuff on pixel art in games or whatever without a valid reason, it kinda ruins it. Technically transparency has been used in games like Super Metroid on the SNES. However, I'm unsure if it uses alpha channels or some special algorithm or whatever that takes from the SNES's color palette and adjusts accordingly to give that illusion. I have no idea if that made any sense though.