Back in the 90s, the SNES vs Genesis debate was raging. Sega would say “blast processing” over and over and that’s all people remembered. Look how fast Sonic moves! Of course, scrolling speed has nothing to do with CPU speed. You could have ported Sonic over to the SNES with no trouble, and he would run just as fast. The idea of “blast processing”, I guess, was that the CPU was faster. According to this page (below), though, the Genesis CPU was really only about 20% faster than SNES.
https://segaretro.org/Sega_Mega_Drive/Hardware_comparison
But SNES was leaps and bounds above the Sega Genesis in every category. More colors. More layers. More sprites. More modes… mode 7 graphics. Etc. etc.
Music is a toss up. SNES was sample based, so it could produce sounds that actually sounded like real musical instruments. However, it had a filter that made the audio sound muffled and cut a lot of the high end out of the sound. Sega Genesis had the FM audio, which was limited but had a big bright full sound all through the full spectrum. Maybe too bright… as many of the soundtracks come across as a bit annoying in their instrument choices (usually using the subpar default instruments given to the musician, using the GEMS tracker that Sega gave all the developers). But some of the tracks really sound great. I can’t decide which was better, but most people say that SNES was better sounding.
Before I go on a tangent though, back to graphics…
So, SNES had more sprites, but very few games needed more than 80 sprites anyway. SNES had more colors, but if you play the same game on both systems, they don’t look THAT different. So, I began to wonder if SNES really was better looking. Let’s investigate. I chose these games specifically to highlight the difference in graphic ability.
Aero the Acro-bat
First the Sega Genesis (Mega Drive) version. Notice the dithering on the face. When you have fewer colors to choose from, you have to dither to get the mid tones.

And then the SNES version. I chose this because I knew it was using the 256 color mode. Notice the face is nice and smooth due to many more colors to choose from. The screen is narrower because the Sega version is in 320 pixel mode (40H), where the SNES version is 256 pixel wide.

Cool Spot
Another game that was released on both systems. Lets look at this intro scene where he’s surfing on a 7-up bottle.

And see the difference with the SNES version. More subtle coloring on the bottle. You might miss it, but you can see the Color Math used for transparency as part of the bottle blends 50% with the ocean behind it.

Earthworm Jim
Again, the Sega Genesis version first. I like this. There is some amazing pixel art going on here, and it looks great, even with the dithering.

The SNES version uses its 3rd layer for a whole different effect. It’s using Color Math to create a lens flare that moves around with the character. The screen is narrower again, which has a negative affect on gameplay (not being able to see what’s coming up next). The colors are a little different. I kind of like the high contrast of the Sega version, but the SNES version looks higher quality.

I think it’s pretty clear that having more colors makes the game look better. I looked at a few other games, and the difference wasn’t so much. You could show me a clip of one at random, and I probably wouldn’t be able to tell which system it was from. But in general, the SNES versions look better.
(On a side note, I’ve heard people say that Earthworm Jim’s soundtrack sounds better on the Sega Genesis. I don’t know, you decide.)
Not enough layers? Fake it.
The SNES, depending on mode, has more layers than the Sega Genesis. The most common SNES mode (mode 1) has 3 layers, vs Sega Genesis had 2 1/2 layers. I say 1/2 because it had something called a “window” which was a non-scrolling layer that was always on the same plane as Plane A. Usually, it was used for a scoreboard (HUD). Ok, you have only 2 layers, but then I saw a game which appeared to have a lot more than 2 layers. In Sunset Riders, about 10 minutes in, you are riding on a train.



The scoreboard/HUD is using the window.
The top of the big mesa is using sprites that move in unison with it. The 2 cacti are using sprites at different priority levels (one is behind Plane A and one is in front of Plane A).
And, of course, Plane A and Plane B are scrolling at different rates, and that is all there is too it. Just a bunch of simple tricks to make 2 layers seem like 5.
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But, can’t you do the same thing with SNES? Yes. SNES has layer priorities and sprite priorities so that 3 layers can seem like 5.. 6.. 7… maybe more, layers. But, the point I was trying to make was to show that a little creativity can make the limitations much less limiting.
So, who wins the console wars? Does it really matter? As long as the game is fun, I don’t thing the player is going to be counting colors or worrying about whether or not there is a 3rd layer. Just have fun. That’s what matters, anyway.