May as well get this out of the way; if you believe Mario is the same with every game and gag like a cat with a hairball when you hear conflicting opinions, you probably won't like this blog post.
The Mario franchise is probably the most well known video game name in the industry. With thirty years of history, the franchise has seen and done a lot of things. In the modern age, I see many N4G users comment on "another Mario" each time a new title is announced. Sometimes it's the title alone that sets them off, or perhaps the subject material. But often the general consensus is that if it's Mario, it's the same as before. And to be honest, I think that's completely incorrect.
Over these decades, the primary titles of the Mario franchise have been platformers involving similar formulas with minor tweaks or power-up upgrades. From the original Super Mario Bros. straight on to Super Mario World, we saw the portly plumber running, jumping and mushroom grabbing to save a princess from game to game (minus Super Mario Bros. 2, aka Doki Doki Panic!!). With Super Mario 64 we saw a slight change where Mario was no longer grabbing mushrooms, but instead stars, now with a full on health system and new quarks and rules applied to his 3D adventure.
Even before this revamp of the formula, Mario had already engaged in kart racing and even a turn-based RPG. Further along in the future was sports games, party games and puzzle games, with Mario Strikers, the Mario Party series and the Mario vs. Donkey Kong games as notable examples. In this regard, I cannot look at Mario games and just assume they are the same over and over.
Now here's a moment of clarity for those with a less than positive opinion of the Mario franchise; the series has existed for THIRTY years. Anyone who has grown up with it and has not seen it grow up with them would probably get tired of it; like an adult who grew out of their favorite Saturday morning cartoon. While the games have done some things differently, the universe has stayed the same for quite a while and it's pretty easy to see why someone would grow tired of that. However Mario is, at its core, a family-safe franchise with consistently high quality simplistic gameplay and probably always will be. To look at this as a flaw would be like telling Disney that Mickey Mouse should be changed after fifty years of lightheartedness. And before throwing the "more adults play games than watch cartoons" argument at me, keep in mind that watching cartoons was at one time an adult's activity during movies and video games in their earlier generations were often marketed as children's toys.
New Super Mario Bros., to me, is a bit of an exception to this ideology. Since its culmination it has served as a throwback to older Mario's 2D gameplay and has brought back classic power-ups and abilities in each iteration with one or two new powers in between. These games have even allowed for an interesting, if not hectic cooperative experience. However, the formula does little to change from game to game, feeling more like expansions with the biggest offender being the latest game on Wii U and its omission of online multiplayer. Thankfully Nintendo is seemingly rectifying the issue somewhat with the Super Luigi U DLC, a single player mode that changes Luigi's movement (he can jump higher but takes longer to stop moving) while ramping up the difficulty in the new levels. This won't change much, but design wise it could serve as a more challenging Mario experience.
Anyway, this is Nintendo's primary franchise and their mascot; and it's the face of gaming. Saying Nintendo needs to give it a rest is like asking Microsoft to stop producing Halo games. I do concede to one point in particular; a LOT of Mario games get produced. We have several coming to the 3DS this year alone and at least two to be revealed at E3 for the Wii U. However, because each one is in different genres and are all different games (not to mention only one of each iteration is released on a system), I think it's at least forgivable, if not ignorable. While Nintendo produces this series (as well as new games like X and some of their newer eShop IPs), Sony and other publishers are there to provide alternatives for gamers looking for something different.
In conclusion, to me Mario is a timeless franchise that constantly brings in new young gamers; that does not need to change. You don't have to like the franchise, in fact I hardly blame anyone who no longer sees the appeal. It's always a red plumber in a cutesy, colorful world and not everyone would be interested in that. To this, I say "I understand, but respectfully disagree." There is a legacy there that continuously brings many gamers both new and experienced into the industry, possibly to become gamers like yourself who may wind up growing out of it and getting into other franchises or like myself who continue to enjoy the games and how they play. The way I see it, both types of gamer can coexist.