Two languages I can think of that have approximately the number of phonemes that some of those sign lists have are Hawai'ian (at least 13 phonemes, depending on how you analyze vowel length and diphthongs) and Central Rotokas (11 phonemes). But that low a number is extremely rare among languages.

"...if you saw those symbols on Mars, would you not consider them a form of communication or language" Communication, yes. Language? Knowing nothing about Martians, I'd have to withhold judgement. On Earth, language is much more than just communication.