I think the visual language of comics, graphic novels, and political cartoons is understandable to many people. I can flip through the pages of a comic book in any language and have a pretty good idea of what's happening.
That said, the relationship that people have with language is pretty personal, so what would be considered "easy and simple" would, of course, vary.
I remember my bilingual English-Spanish dad saying that Spanish was a more expressive language than English, that he felt emotions more strongly in English. But Spanish was his first language.
For pronunciation, Japanese would be an easy language for you as a Spanish speaker since the vowels are the same. It would be easier for you to sound more like a native than for an English speaker. The writing system would be difficult for you, but not for Chinese speakers since Japanese includes kanji (Chinese characters).
There must be other examples as well. But I think you're pretty safe with drawings (and emoticons, too!) ^_^