NSMBU is only disliked on forums by a few individuals. My friends and family with kids which are super casual gamers all love it. I mean I don't know I might be wrong just making a prediction for fun. Also you said only switch right. So sales are gonna die right when switch 2 comes out.

NSMB fatigue wasn't just a thing on forums, it showed in sales as well, both for NSMBU and 2; Switch and 3DS both had proportionately lower sales of NSMB than Wii because of this.

Personally I doubt Switch 2's release will kill sales of Wonder, there's still a massive base of Switch owners and they won't all buy it immediately. 3DS games didn't just instantly stop selling after Switch came out.

Well see what happens but I feel there might be some mario fatigue. Like sure NSMBU and 3d world were ports but no one really  owned a wiiu compared to 100 million switches and just on Switch alone that's gonna be 4 mario platformers witch  mario wonder. My prediction is 20 million on Switch. 

Lazy full priced ports that weren't marketed....  and still sold well.

Nintendo had commercials for NSMBU.  Yes they were ports but most people didn't get to play them because wiiu sold like 13 million WW. Let's not forget the best selling game on switch is a port.

Mild marketing isn't the same as strong.  Pikmin 4 was the first in the series to be really marketed and it sold far better than previous entries.

Yeah and MK8 wasn't a straight port, it had all kinds of DLC added.  

Time will tell but using NSMB as a marker for what Wonder will do is a mistake imho.  It will have a much stronger marketing campaign.

Probably that's why I put it way above NSMBU when you consider that switch 2 is coming out next year we are comparing 4 years of sales vs 1.

Assuming switch 2 is BC, I don't see it's launch hurting sales.  I think Wonder hits 30 million easily.  Spider 2 will not, unless Sony gives it away for free via bundles which isn't a fair comparison.  Huge difference between selling something versus giving it away.

I think Spider-Man 2 will sell somewhere between 20-25 million copies on PS5 alone. Mario Wonder will sell over 30 million on Switch 1, as the fanbase is thirsty for a fresh 2D Mario. Spider-Man 2 would be lucky to clear 700k in Japan, Mario Wonder will exceed 7 million. To put it in another way: Spider-Man 2 has to beat Wonder by 6 million units outside Japan to get a tie worldwide.

Japan is a big factor for Nintendo and virtually a non-factor for Sony's games.

The thread never mentioned bundled sales don't count.