It's perfect for what it strives to be.
Two dimensional Mario games are a sure way to earn some money while maintaining the faith in quality as well as refurbishing the same old thing for God-knows how many times. Nintendo is as guilty of rehashing ideas that have yielded great success as any other developer out there. Though not everything is as we had hoped.
Some stylistic choices are immortal, they don't come close to ever being made outdated. Donkey Kong Country and Super Mario World are such examples. Their gameplay/style could be made indefinitely until the end of time itself, no one would complain. The fact that the style of Super Mario World was quickly phased out bugs me, the handheld days could have been fruitful in that regard. Do not want to be stuck in the past? Great, but those aren't old ideas, they're gold ideas.
Super Mario Maker actually tries to cater to those who have tried to further their fix on 2-D Mario for as long as the internet was something of a fertile ground for original ideas that wouldn't have a chance in the mainstream. Softwares were designed to create brand new stages of classic games like Super Mario World and such. Some people went as far as creating whole new worlds to offer a complete experience.
Now Nintendo takes the basic creation aspect that games like Minecraft have brought into the industry to something more the liking of old-seasoned gamers. It's simple really, you have the general aesthetic of such games as Super Mario Bros., Super Mario Bros. 3, Super Mario World and New Super Mario Bros. and give players the opportunity to create and share levels.
You have a built-in engine emulating those games workable in Super Mario Maker, whatever the gameplay was like in determined game it will be maintained in whatever level played for that game. For example, in the first Mario you couldn't grab shells, so you can't grab shells when playing levels made in the style of the first NES games, the others allow Mario to perform that.
Stuff found in newer games are only possible in the levels that play like New Super Mario Bro. like the wall-kicking trick. While creating a level you can interchange the style of the games but be aware that if your level uses wall-kicking to allow beating then you'd be facing an unbeatable level in any other Mario engine, unless you offer some kind of work-around trick.
You even have a few added-in levels built by the creator but they won't last long, what's actually juicy here the the full possibility of connecting to the Mario community as a whole and play courses made from people all around the world for all the different regions this games is available to be played at.
The difficulty of these levels go from levels that you don't even have to press any button to beat -- the the so called-ed automaton courses -- to levels that only a handful of people from the thousands upon thousands who have attempted actually managed to beat them. One thing is certain, if a level exists in the system it can be completed, how hard it is stands as the real question.
There are four difficulty levels that take differing difficult sub-settings and present the player. In the first difficulty you only have to beat 8 levels in order to complete the cycle. In higher difficulties you have to beat 16 levels. To do that you have 100 lives, which might sound like a lot, but in higher difficulty settings they will be extinguished faster than you imagine.
By beating 100-lives challenges you unlock new skins for level design. The actual requirement for unlocking stuff for different designs -- like the engines of other games like Super Mario World -- is simply spend time on the course creating screen and dealing with its structure. Creating levels is super simple and intuitive, you simply choose what you want to add and manually do so using the tablet-controller. Everything is as simple as touching the grid screen while selecting the aspect you desire.
This type of games are meant to be peer to peer, sharing and all that stuff; though if you never want to create anything and just aspire to have a limitless Mario source you're bound to find Super Mario Maker with open arms just waiting to start the marathon. It's basically impossible to run out of courses to play. Granted, not all of them offer a good experience, in fact the majority are complete crap, but still, among the incredible bad design ranging from cheap tricks to courses that only require the player to run/walk to the finish lines you might find some golden challenges that are worth your time.
Whenever a course is uploaded it starts tracking the first person to ever beat it and the world record time. You have highlights with some of the best creations in any given week, the latest additions for those willing to delve into the newer, fresher stuff, and even some event courses designed by some popular people or for some kind of championship. It's true that most of these popular guys are Japanese gaming news icons and are basically unknown by westerners, but still.
There are many things that could be said about the system regarding how the levels are chosen for each new marathon, though you don't have to actually cope with terrible design if you decide so. When facing a 100-lives marathon and you run out of hope of beating or having any fun at all with any course you can simply hold the "-" button to skip it.
The community built over it isn't all too connected to tell the truth. Nintendo is still stuck in the past when it comes to building an online system that actually welcomes the players, though it serves the basic purpose of delivering new courses at a rate never imaginable. Who would have thought this could be possible in the old days of 1992 for example that such a feat of limitless Mario could be even imaginable? Not many people I'm sure.
When you play a course and you decide it should be rewarded you can give the creator a star. Getting more starts will earn you more popularity but that about it. The popularity built around famous creators is pretty much set in stone by now. Some features that were available at launch aren't really functional anymore because of the changes made on the Nintendo's Miiverse. Ever since it came down the commentaries left when people died have been whipped out, remaining only a sound X bubble to tell its history of once having been there. Not actually a huge loss though it offered some good comments here and there.
The game as a whole is pretty bare, like it is stripped down to its basics of level sharing and playing endless streams of stages created by other players. There's nothing really missing in that one aspect, though nothing beyond this is offered, nor even hinted at. The simple premise of replaying some of the the classic and even the recent engines of Mario until the end of times is sufficient to make up any mind about whether or not this should be an instant buy or something unworldly unthinkable.
2D Mario players should be enthusiastic about this. You might not spend hundreds of hours because at some point you realize that nothing will ever beat the perfection that game design was in the original games, but it's certainly more worth it than another New Super Mario experience or some random recreation of the classic games over the internet. It's amazing for what it is.