It's an idiom. the literal meaning is "it goes", but it's used most often as a response to "Wie geht's" or "how are you".
Fitting with the precedent of how Duolingo handles other idiomatic phrases, that should be accepted so report it if not.
But you should know that when a German says es geht, especially in the context of you asking how they are doing, it means something noncommittal somewhere between "well" and "terribly".
Sorry i am not a native english speaker, so what do you mean by noncommittal, and is there "so so" thing in english?
I believe noncommital just means it falls between well and terribly and is liable to change easily. So-so is a phrase in English, and going along with the OP's question, I have rarely but occasionally heard "It goes" or "It's going" as a similarly noncommital response to "How's it going?"
Noncommittal is 'not expressing or revealing commitment to a definite opinion', so its a vague answer, like answering "Okay", "So-so", and so on. Both are common English phrases.
(native English here) I can picture myself nodding my head up and down when saying "It's going all right" and gesturing with a shoulder shrug when saying 'So so" - in both cases I am acknowledging the person's question without going into details (unless I want to). Sorry if I'm too off topic with intent of this discussion thread.
How about sth like "it's fine" along with the alternate expressions given in the other comments?
Two pass reply: - In the realm of idioms, if one were to say “It’s fine!” with the enthusiasm of an adolescent reflecting after their first kiss, versus the same reply from a tenured I’m-just-glad-to-be-home employee: same words, different meaning. - From a monotone stance, It’s uber-tastic, It’s great, It’s fine, It’s alright, It’s par, It could be better, It’s …., these relay levels of personal wellbeing without visual or auditory cues. Sumary: Until Duo offers full emersion VR, may be best to think in terms of monotone answers.
I'm surprised I haven't seen anyone post "It's going". Someone asks you "How's it going?", you say "It's going" as an indifferent, noncommittal answer.
Yes. This. "How's it going?" "It goes". The tone carries the meaning. I do not like Duolingo deciding a replacement idiom. The literal translation here works well.
I'm guessing they chose "So so" because it's relatively common in English and has basically the same meaning. But yes, the literal translation works well, too.