When someone is a European game snob of that era they are almost assuredly referring to Amiga games like those produced by Psygnosis(e.g. Shadow of the Beast) which have some gorgeous painterly work in them, make good use of the hardware, play smoothly with largish sprites, and on occasion, showcased parallax scrolling effects. There were some pretty solid side-scroller and shooter games made for that platform - it was the lead for "Another World", which was groundbreaking on a number of levels. And there were also many games on that platform that were mostly-static adventure games not of the Sierra or Lucasarts imprint, but beautiful looking all the same: Silmarils made some of those, as did Horrorsoft.
That said, those kinds of games weren't actually the norm on the Amiga, either - there was far more low-end drek that threw higher fidelity, but artistically underwhelming, graphics on the screen sluggishly and semi-competently(ports from other platforms, licensed tie-ins). Console games did tend to have a higher average level of polish along most axes.
Amiga had graphics almost on par with arcade machines (the golden standard of the time), have you actually looked at some screenshots of Shadow of the Beast and other Amiga games? Yes SMW had a great art style (I love it!) but it used simplified/cartoonish shapes. I still think Amiga was the best graphics you could get at home, unless you were so rich that you could buy arcade cabinets.
I'm not really interested in getting into some kind of Amiga vs PC fanboy debate. Those were tedious in 1990 let alone now.
But Shadow of the Beast, while an impressive game for the time and for the Amiga is not on par with SMW technically. You may prefer the art style of Shadow of the Beast, and that's fine, style is subjective. But technically SMW is just doing a lot more. The multi-layer parallax in Shadow of the Beast is only used on the flat levels without any level architecture, Shadow of the Beast has few frames of animation per enemy, and fewer colors per enemy, and fewer colors on screen (128 vs. 256.) I don't have the details of the Shadow of the Beast level engine but it seems like the levels are also made out of much larger blocks than levels in SMW.
Anyway, this conversation is getting boring and like I said I'm really not interested in any kind of "Amiga is the best of all times" shenanigans. I'm not a fanboy of any particular hardware, console, computer or otherwise. Every platform had good games, and things that were good about it and things that were less good about it. This thread was about SMW.
I don't understand why you want to slap the fanboy tag on me, when I actually said in my comment that I love both games. Also, sorry if I got you bored, I usually enjoy talking about technicalities and often forget that others around me might be uninterested.
I accept your point about the colour mode, it seems [1] that SMW has more colours on screen as you said.
Regarding the animation frames, I couldn't find info, I'd love to read about it so let me know if you have any good link.
In my parent comment I was thinking more about smaller vs larger sprites (up to 128px in SotB) [1][2], and flat colours vs extensive use of gradients (I don't have hard data on this but it seems pretty evident by just looking at a few screenshots).
That said, those kinds of games weren't actually the norm on the Amiga, either - there was far more low-end drek that threw higher fidelity, but artistically underwhelming, graphics on the screen sluggishly and semi-competently(ports from other platforms, licensed tie-ins). Console games did tend to have a higher average level of polish along most axes.