i think it will be a success like splatoon for sure

I'm expecting somewhere in the low 80's with most major publications giving it an 8/10 or 8.5/10. Despite this, I do expect low scores due to content not being available at launch.

Critics will complain about the daily content distribution, so less than 90 is a given, sadly, because Wii U hasn't scored any 90+ game this year.

Probably 85, but I wouldn't be surprised if it scores less.

Im guessing they all have to wait for 9 days to unlock all of those stuff?

I would say 88
Im not sure how reviewers normally reviews a level creator game. But im guessing they would mark it based on the options they have.

You can just change the date on your console to unlock everything the first day.

88

92

It will be in the mid to low 80's. As others have said there have been other great 2d nintendo games that just dont score as highly as they deserve. Itll get a lot of very good reviews but some reviewers will manage to find things to complain about that will seem crazy to me and drag the meta score down.

Well I haven't heard a bad thing about it so far. But at the same time, reviewers will have a bit of an unrepresentative view because they won't have the benefit of millions of people contributing levels.
I think it'll be quite high. Definitely 85. 90 would be good. Dunno if you could expect much more than that for a level-editor though.