That should be the submission title, per HN rules.
In fact, many relatively credible places I've seen, like my national-language Wikipedia use the word "impossible" - I just want to break the myth :).
BTW: In the rules, I can only see "Please don't do things to make titles stand out, like using uppercase or exclamation points, or saying how great an article is. It's implicit in submitting something that you think it's important." - I don't think my submissions breaks this rule (please let me know if it does!). To adress the other point, the original title/name is in the README (and it's MalbolgeLisp v1.1, or the repo name, as you wish - malbolge-lisp), not in the Github description. I felt like it's not descriptive enough and might be misleading (since you could interpret it as a malbolge interpeter _in_ lisp).
Otherwise please use the original title, unless it is misleading or linkbait; don't editorialize.
> Malbolge Lisp is an "almost impossible" language, ...
"Be kind. Don't be snarky. [...]"
(you could have phrased this like "i'd have preferred if the author didn't use clickbaity terms and instead used (...)")
"Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."
(you interpreted the "impossible" as something done for attention grabbing, while it's quite clearly simply a shorter and more interesting way to say very difficult)
"Eschew flamebait. Avoid unrelated controversies and generic tangents."
> Malbolge is a public domain esoteric programming language. It was specifically designed to be almost impossible to use, via a counter-intuitive 'crazy operation', trinary arithmetic, and self-modifying code.