I would like to hear somone old enough, who lived in early Mario/Nintendo times  when Mario was created...

How it became so huge, how did Nintendo make a plumber biggest character ever, how did they market etc..

When I try to solve Mario's mystery, my head explodes.

Super Mario Bros. (not Mario Bros.) started with one simple concept: jumping is fun.

The entire game was built around that one concept and that's how Super Mario Bros. came to be.  Being a plumber in the mushroom kingdom was more of an afterthought.

super mario bros defined the side-scrolling patformer and it almost single handedly saved gaming, and then Mario 64 showed how a 3D platformer should be played, and mario kart created a sub genre in the racing genre, mario has been in some of the best games ever, its only natural that would make him so popular.

the same way how people love a mouse that is yellow & has red cheeks

They both began a phenomenol series/franchise

{even though pikachu didn't technically begin it}

Super Mario Bros. was the game you had to play when I was a kid. There were plenty of other games on the system that were good, but Super Mario was the first game you played and the first one you showed to friends. It served the same purpose as Wii fit. It was what let you try out your new system and understand it. Super Mario world did the same thing, showcase the system. Mario 64 showcased the system and introduced 3d gaming.

There was also the merchandise and Cartoon. I remember those fondly, yet I bet trying to rewatch the old show would be ... disappointing.

Maybe you had to live it to understand the growth of his appeal. Several of the biggest advances in gaming from my childhood were ushered in by Mario, so to me he is gaming.

Go play some Atari and Arcade games before SMB came out, then imagine that those were the only games available, save for PC games. Then play SMB, and you might get what's going on.

But how did Nintendo make it happen?Certainly there was maybe even better games than Mario, and from 80s to this day there certainly is better games than Mario series, but you see only Mario in tv (like Simpsons), and EVERYONE knows Mario.

There were other good games back then, but not much that is really better. Back then we had a few less genres, and many of the other genres were still - by our modern terms- primitive. There aren't many platformers in the same league as SMB and SMB 3. Megaman, Ducktales, Rescue Rangers, and a few others. Samus evuntually went to FPS. Sonic and Megaman are shadows of themselves. Mario is the only one that maintained his ability to maintain high quality and innovate in platforming.

Also, the Atari platformers have nothing on SMB. I like some of them. Pitfall is classic, but SMB really takes the genre further.

Add in his cross genre appeal with SNES Mario Kart and N64 Smash bros. and you have an icon.

You might as well ask Wii Sport players why they bought a WII. Mario was the system seller back then.

I loved and still love Megamans over Marios on Super Nintendo/Gba, but at Ps2 era Megaman couldn't keep up on big consoles unlike Mario...Megaman Zeros were last series I truly enjoyed (and I have played all of them).

Please, please tell me you've played the game at least.