I like this kata a lot-- learned a lot about how numbers/coercion works in javascript by reading the other answers.
Will say it felt a tad easy for kyu 5 though.

Imo, there should be a case in the basic tests where the starting floor isn't the top, or at least that it should call a bit more attention to it in the instructions.
I could be wrong, but it seems like an unintended "gotcha" for this problem when it's not clear that that's the case causing your code to fail.

This seemed a bit harder than the other 6 kyu problems out there.

Some of that is because of the noted unclear instructions ("rotate it left" is not a clear shorthand for "move the first character to the last position in the string".

But also this was just harder to do, even once instructions were understood (imo of course).