To date, there are no Mario games that allow players to completely create levels and share them with others. However, Nintendo is, in fact, considering allowing users to create their own Mario levels in future titles.
New Super Mario Bros. U Director Masataka Takemoto says there is a possibility that players will be able to create their own levels in future Mario games, but only if there is a way to make the feature unique and attractive to beginners and core Mario fans alike.
“I think the Coin Edit feature in Coin Battle is a step closer to that. There is a possibility of this happening in the future, but there’s no use just blindly making that feature available. We would need to carefully think about how to make such a system work. The important thing is that it has to be something that is uniquely Nintendo. Where a beginner can easily make something and have a good time, and simultaneously, someone who is really into Mario can delve into it deeper and make something more complex. So that is a challenge we will need to tackle in the future.”