It is a dialect, written form is German.
It is like hearing French spoken in sub Saharan Africa, it is hard to grasp but eventually you get it
Both things are wrong. It's not a dialect in the sense that it is not the same language with special intonation, some new words and new idiomatic sentences. It has its own (much simpler) conjugation and declension scheme. Much closer in feel to a creole.
Its written form is also not german. Good luck reading some of the züri by mike comic strips as a german reader.
If by "eventually you get it" you mean "after putting enough effort into learning it", then yes. But that's the same for every language.
If you mean "you need a few hours to get used to it and then you understand almost everything", then... well... not at all.