Have to express similar sentiment towards not being enthused by the idea of an open world Mario game. Mainly because I greatly prefer the side-scrolling Marios and 3D world to the Marios from 64 to Galaxy 2, due to the generally shorter levels and smaller spaces of the non-mainline Marios.

The idea of collecting stars and coins doesn't interest me, whether it be because I can or for kart upgrades. Exploration for the sake of exploration is equally unexciting.  I could become interested in an open world Mario game, if it were as different from the 3D Marios as Super Mario Bros. 2 is from the other 2D Marios.

Want to say a combination of Minecraft and Mario could get me excited, since Minecraft is one of the only two open world games I like. Yet, I have to remind myself I only enjoy Minecraft due to mods only available on the PC.

I don't think open world is the kind of genre that could really work for Mario. I still think that our next traditional 3D Mario game is overdue though.

I say "why not?" I imagine Miyamato could come up with some great stuff and it could be fresh. The more I think about it the more I like the idea.

"Open World" in a way Sunshine and 64 did would be pretty awesome.

Just give me a Mario game in the 64 style but bigger and better and I could die a happy man. I think we should setup a kick start for it

An open world really makes no sense for a platformer.

In Lego City the camera transitions from a 3D position to 2D seamlessly letting you play 2D platform tracks with the camera in a fix position. When you are done with the platforming you transition back to 3D when you reach the goal. The size of Lego City is big enough and it has secrets everywhere.
I am not sure why a lot of peope think less of Mario Sunshine but it had a lot of Open World kind of puzzles with freely rotating camera. Both in the city areas and also in some of the tracks. (Freely rotating camera is always going to be a problem with puzzles)
I loved running around exploring everything. Not very many people have played Mario Sunshine: really needs a HD remake.
If the different sections of Sunshine Island could be merged together the Island size would be quite enough.

a huge hub world is good enough i think

Mario 64 is still my favorite Mario game of all time.

I don't see how that could be made interesting...you seemed to avoid speaking about the gameplay in your blog post. I see Mario games as being master-classes of level design, which is their main draw. Because you can't control a player in an open world (without it losing what makes it open), you can't have that tight level design. Because of that, what do you have to ride on? The gameplay of Mario games is fantastic, but would it work if you were given a giant open space to play around in? And how would the game be structured? Would it be completely alinear? Most open world games tend to rely on missions to progress the game, but how would missions work in the Mario universe?

I think having levels is the best way to go for Mario games, but I wouldn't be opposed to having some being bigger and more focused on exploration. i don't think Mario needs a full open world though, I honestly don't really see how that would make the game better. Seems like it would just water it down.