I don't know if anyone has asked this or not, but... Would Sonic still be as popular, well known, and loved as he is now if he was never a video game icon? What if he was only a cartoon, or worse, if he was only a comic book character? I can't help thinking that if you removed the gaming aspect from Sonic, his friends, and his adventures, you'd have something very similar to Sonic X. The self contained stories would be great for a short run, but there would be no meaningful character development or story lore. As a cartoon, it would just linger around, and it would ultimately become a boring show that doesn't know what to do with itself; other than promote toys or something. In fact, I kind of think Sonic would NEED to become more like the Archie comics or something. You'd need to have deeper character development, a deeper story, a deeper lore, and so much more just to keep it interesting. And if they could somehow manage to capture the wondrous magic and charm that made many of the games so memorable, it'd be perfect. I never was really into the comics myself, so fans of the comics will have to step up their game and answer this question as well. I strongly don't think a comic, or manga, of any kind would last very long without something else to back it up. If not a game, then a cartoon, or a movie, or something. DC and Marvel have kept its heroes alive this long because of things like that. I could be wrong, but I just don't see comics surviving that long without some other medium to bring in more fans. But then again, I guess you never know what will become popular or an overnight sensation. Not to compare, but I don't think anyone could have predicted things like My Little Pony or Adventure Time to become as big and popular as they are. Even books, like Harry Potter and the dreadful Twilight saga had huge amounts of fans and readers.
There would have to be movies of some sort if there were no games....but then again, Pokemon would have been nothing without the games.
Dude you really answered your own question there but to add to it from another angle, would Dragonball and Dragonball Z be as popular if it was just a video game? It really comes down to how good the main product is and if the original works are of an extremely high quality, then it's legacy will live on indefinitely in the hearts of the fans.
Trying to develop a character like Sonic too much would be a disaster. Would Sonic be more compelling if we discovered that his desire to play the hero comes from when Uncle Jimmy snuck into young Sonic's bedroom one night and brutally forced him to tug his prick? Would Sonic be more compelling if his drive to be the fastest thing alive comes from his mother being flattened by a truck while crossing the road? Please, do me a fucking favour! All we should know about Sonic is that he's blue, fast and is always there to be the hero and tear down Robotniks shit and save the day. For everything else, Sonic should be a blank canvas, I.e. whatever you want him to be. That's one of many reasons why Classic Sonic and Classic James Bond were such phenomenal successes. Take a look at the beautifully simple world of Mickey Mouse, how deep did we delve into his psyche over the past 100 years? Exactly! Not fucking much at all.
Lets consider The Phantom as a case study. He is the longest runnning comic book character still syndicated in newspapers today, with a comic book run over 1500 issues - the longest continuing run of comic books ever. Yes, there has been some abortive attempts at branching in to other mediums, including the campy cartoon Defenders of the Earth, the train wreck that was The Phantom movie (Slam Evil! Yeah!) and the oft forgotten Phantom 2040. I would argue that all of those have detracted from the brand to some extent, yet the character lives on - The Man Who Cannot Die. The enduring quality of the Phantom comes down to the fact that the stories are simply and elegantly told, with good humour and grace. You can rest assured that the Phantom always saves the day with his jungle cunning and wits - a notalgic throwback to quaint and happy times. Unlike his emo and angsty clone Batman, The Phantom has very few recurring villians, he is never over-shadowed by the nemesis. Sure, there is plenty of lore to soak up if the fancy takes you, but anyone can jump in with the pre-requisite 3 panel back-story "For those who came in late" and enjoy a self-contained good old fashioned yarn. I can't see Sonic having the same success. In essence, his character design is a joyless, soulless corporate shell that shamelessly copies aspects of more enduring characters, namely original steamboat Mickey, Felix and Roadrunner/Speedy Gonzales with a 90's 'tude bent. Outside of the video game sphere, he might have survived a short while, but the me-too-ism would have caught up with him eventually, especially when the 90's 'tude became passé. On the other hand, I can't see Mario existing outside of the video game universe either. While his design is more original than Sonic's, I can't see the character really going anywhere or doing anything. Mario is the quintessential everyman, so in essense he is also an empty shell without substance, although arguably by conscious design
I think if it wasn't for the games, Sonic would by now have probably gone into obscurity along with cartoons such as 'Bucky O'Hare', 'Skeleton Warriors' and 'Mighty Max'.
Isn't this what happened anyway, up until lately? Anyway, Sonic's popularity comes from it being a good game. It's like asking what if Sonic was actually a brand of car that was good in the 90's, would it still be going now? No one would know that for sure, but it seems silly to think of such situations.
Sonic is like a BMW 5 series. Awesome in the 90s, ugly as shit and soulless in the 00s, picking up a bit in the 10s.