Does this work correctly for the case of DPDD?

How so? Can you give an example?

I'm sorry, I should have been more clear.

First, let me say that I am commenting on the Ruby translation. The JS translation does not seem to have this issue, as the description specifies the numbers you receive will vary ("1 through 10 or less").

The issue is not that the input does not change; the issue is that, for all stated possible input values, the return value of the function will be the same.

In languages other than JS, you will receive the same 10 numbers in an array every time. Sorting these different inputs will always result in the same array. This means that the solution will ALWAYS be to simply return the following string:
"10 9 8 7 6 5 4 3 2 1 liftoff!"

Thus, a valid solution can safely ignore the input parameter. Having the parameter be there at all seems intentionally misleading.

If the other translations worked the same as a JS solution, where the given numbers were not always 1 through 10, this would not be an issue.

How does it vary based on input? What input could you give to the function that would return a different string?

The initial F# solution contains a tab character, which throws an error when run.

Thanks for looking into it.
FYI, the initial solution returns s[0], which is of type char, so the initial solution doesn't compile.

The C# translation initial code has the return type as "char", but all the tests expect a return type of "string".

Specify units

Kata description does not specify what to do in scenarios when there is no occurrence of "x" in the string

What is a "lost number"? I'm guessing it has something to do with the show I've never seen, and they are not numbers that took a wrong turn on their way to the number line, but I was quite confused at first.

Why are there 300 test cases?