I'm creating a Super Mario level editor, would it be considered as a "remake" of SMM?

[Mariusco]

I don't believe making a Mario fan game with a level editor automatically makes it a Super Mario Maker clone. I am the creator of Super Mario Construct which is also a Mario level designer, but it's got a much different philosophy. SMM focuses mainly on ease-of-use by keeping the amount of content simple and small to cater to casual level designers, but this goes at the cost of introducing a lot of limits to what the level designer can do.

Meanwhile most Mario fan-editors out there are vastly different in that regard, they're more expansive and you have much more freedom with what you can do with your levels, but that comes at a cost of the level editor having a bit of a learning curve.

There are some Mario fan-editors that do intentionally try to mimic the appeal of Super Mario Maker though, intentionally making the UI similar and branding themselves as a PC Mario Maker. That's fine by me, but I would recommend staying clear of that direction since there are already a lot of SMM fangames out there.

I see you and other user said I'd have to make a different user interface, I don't think it will be so hard but there are many and not many ways to display an item selection at the same time (without looking like the official games). Anyways, thanks for the comment!