I have studied Toki pona for a little while in the past. It's emphasis is on minimalism and context. Especially since the Lexicon is around 130 words. It sounds like things can be ambiguous, but once you get a hang of it communicating is pretty easy.

In my opinion this allows you to learn the grammar and how to speak relatively easily( which is also helped by the fact that there are relatively few grammar Concepts)

Further there is an offshoot of the community called Toki ma, where it's emphasis is on building on the Concepts that are from Toki pona and extending them to be more of an aux lang and to be more fledged out as to be able to discuss complicated Topics.

With all that said, I really would like to see some sort of version of this for other languages. From my limited language learning it seems there's a huge learning curve in the beginning that can somewhat taper off after you get a good handle on a language's grammar. For example knowing definitively three to four hundred words you must know to be able to speak basic Japanese/Spanish/French etc, cuts down on your study requirements.

There are of course arguments against this, but it seems like a cool idea.