What's the sense of the German phrase 'morgen noch mal'?

I have some idea that it’s ‘tomorrow again’, but I am worried it has a more idiomatic meaning.

Context:
Just played a chess game with a stranger over the web. On winning, I said ‘Gutes spiel’ Opponent said ‘war nicht so gut’, then typed a new line, ‘morgen noch mal.’

Literally, tomorrow again, but maybe an American would say “tomorrow is another day” (think Gone with the Wind), given his earlier statement of “war nicht so gut” (was not so good)

it could also be fairly translated as “we’ll do it again tomorrow”

I understand language is ambigous so maybe it’s too hard to tell. But so far we have two different opinions. Maybe we need a native speaker or three hundred thousand to give us a representative opinion? I checked the online dictionary Leo but got no love on the question.

As others have already said, it means roughly ‘again tomorrow’. You’re overthinking it. Imagine a German trying to wring deeper meanings out of ‘try again tomorrow’. Yeah, someone could use a simple phrase in a loaded way, but semantic analysis is never going to reveal that. He gave you a bit of encouragement, “give 'em hell tomorrow”, leave it at that.

your question: gutes spiel = Good game
answer: war nicht so gut = wasn’t so good
2nd answer: morgen noch mal = tomorrow again

It might also have been a question to you to play again tomorrow… forgot the ?

But no idiomatic meaning there.

I’m a native speaker of German, and I have never encountered the phrase. Of course, the translation as “tomorrow again” or “another time tomorrow” is correct, and the context is quite clear (at least to me) that the intended meaning was something like “That game wasn’t so good, but maybe I’ll do better tomorrow”. It’s not idiomatic, however, unless it’s a regional idiom that I am not aware of.

Noch mal generally has the sense of “one more time” or “again”. In your situation I would take it as “let’s play again tomorrow”. Nothing sinister at all.

After you’ve finished your glass of fine, German Pils you might tell the bartender “noch eins, bitte” - one more please.

Thanks for all the great replies!