What are the different versions of Sonic the Hedgehog (1991) and what differs between them?

So, it is my understanding that while most of the ports of Sonic the Hedgehog 1991 are straight ports, there are a few officially-released versions of the game out there with gameplay differences. Here are the different "versions" of the game that I know of:

Sonic the Hedgehog (US release) (Genesis) - The original release
Sonic the Hedgehog (JP release) (Genesis) - A few minor changes associated with this version. The clouds move in Green Hill Zone, the water ripples in Labyrinth Zone, the stages are in order in the level select screen, and some bugs have been fixed. This version was the one featured in Sonic Jam.
Sonic the Hedgehog Genesis (Game Boy Advance) - This port adds in the spin dash from Sonic the Hedgehog 2 as well as a few additional features. However, this port is infamous for its bugs, glitches, and slowdown.
Sonic the Hedgehog (iOS/Android) - This port adds the spin dash as well as Tails and Knuckles into the game. Some levels have been slightly redesigned.
3D Sonic the Hedgehog (3DS) - Sonic the Hedgehog with the spin dash and 3D graphics.

So, my question are thus:

Did I miss any major game revisions in the list that I have?
Did I miss out on other official ports that include game changes? I do not want any ROMhacks the be included in the answer.

version-differences sonic-the-hedgehog

Best Answer

user106385 gave a quite complete answer.

I would add a point that I found very important for all games based on reflexes (so most of all):
Due to the 50Hz refresh rate of the PAL/Secam format in Europe, games played with European Megadrives and TVs run a bit slower than the 60Hz of NTSC format.
Particularly striking is how the music sounds different (not to speak about how the gameplay feels different).

Here is a video showing the differences:

And one explaining this difference more in details:

Pictures about "What are the different versions of Sonic the Hedgehog (1991) and what differs between them?"

What are the different versions of Sonic the Hedgehog (1991) and what differs between them? - What Text on a Pink Surface

What are the different versions of Sonic the Hedgehog (1991) and what differs between them? - Photo of Women Sitting on Orange Sofa

What are the different versions of Sonic the Hedgehog (1991) and what differs between them? - selective focus photo of a red tulip flower

How many versions of Sonic 1 are there?

Sonic the Hedgehog, the Mega Drive Re-Release Saga In fact, the Sega Megadrive received four different versions of Sonic's first adventure across three different compilation titles packed with other Genesis games, plus a re-release with the \u201cSega Classics\u201d logo.

What is the oldest version of Sonic?

While Sonic's first game came out in 1991, the character's first appearance was in a racing game called Rad Mobile. He was the ornament on the rearview mirror, a miniature version of the classic '90s style. Sonic went on to star in a number of sequels and spinoffs, like Sonic Spinball.

Comparing Every Sonic The Hedgehog (1991) Comic Adaptation

Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.

Images: Maria Orlova, Ann H, RF._.studio, João Jesus