I'll preface this by saying I think Jenny Slate is a talented actor and and incredible voice-over actor. I have followed her career and enjoy just about all she does.
That being said, I found this difficult to watch. I wanted to like it, but it felt amateurish and awkward. And not particularly funny at all. I know this wasn't billed as pure stand up per se, but for me (as all reviews are just opinions) this isn't her realm. Stand up takes years to master, and putting together a "set" takes lots of work and re-work, trying out material on audiences and making adjustments and timing is key. This felt more like stream of consciousness with a few pre-planned anecdotes. It felt clear these were unchartered waters.
I see that some people vibed with it. She is intriguing (i'd love to have a beer and conversation with her) and and her quirkiness, along with some home footage and interviews were enough to be entertained.
I did note at least one person thinking the negative feedback thus far is based on taking a jab at the patriarchy and government. Yeah, someone is always offended by something, but I'm a white dude and thought they were cool sentiments. Just didn't work for me overall.
I'll keep watching and rooting for Jenny, but my guess is, the consensus will be that this experiment won't be considered one of her successes; in a career filled with them.