I'm not the author of the Kata nor am I able to edit the Kata, so unfortunately the testcases won't change unless edited by the author.

The testcase's expected and actual are swapped around, so your solution is returning "FalseFalseTrueFalseFalseFalseTrueFalseFalseTrueFalseTrueFalse..." and the expected result is "Ths wbst s fr lsrs LL!". Other than that, the C# version works fine - double check your code.

fixed...

Thanks for reasuring me of this issue, I'll get to it when I can.

Very good!

So "chucklu", you can check your very good thoughts and hints on the harder version!

(Maybe I will translate part 2 also in C#. Then with recursion. ;-))

Well... that's ok because this is the simple version of the Kata, the harder version in wich I will add the test case will be part II so I will make the iussue as solved, sorry for the inconveniences.

Have your really looked into the test cases? There are many test cases (8!!) and random tests. Look at "Show Kata Test Cases" above! There you can see all real tests!
Only the example tests have one test. This is normally here in cw.

Perhaps I didn't understand, what you really meant... ;-)
So please describe the problem more.

Your code is no testcase. Where is the Assert with the expected value?

Generally where is the problem? The test cases are translated from the JS-Version.

is this C#?

Same here,

_0_BasicTests
Expected: null
But was: 123
at KataTest._0_BasicTests () [0x00000] in :0
_1_RandomTests
Test Passed

After passing _0_BasicTests in the first run. Are they not the same?

Your code is actually failing before -0, it fails on 00 which expects false and you output it to the console

Console.WriteLine(s);
Console.WriteLine(flag);

which produces

00
True

And then you return true for 00...

"-0" is supposed to return false, as far as I can tell test checks for that in C# version as well.