One day, someone is going to challenge Hall to write a book with two main characters who BOTH have reasonably healthy families and I think it might break him.
In the meantime, though, his ongoing exploration of the overeducated and underselfesteemed will never cease to hit the spot.

Hall is very good and part of the reason he is so delightful is just how he writes. From the absurd referential conversations (I'm thinking of the "which character are you from Aladdin" conversation) to his neologisms, to his exuberance. If Terry Pratchett has been about thirty years younger and writing introspective romances, he might sound a bit like Alexis Hall.
The other thing is that Hall knows what's funny. What is funny in the story of a deeply stressed and anxious person is not that they say the wrong thing, but that the wrong thing itself is absurd and wandering around being human is absurd and if you don't laugh at it, you'll cry. (His characters do that too.) So while you feel like you're being invited to laugh, you're not being invited to laugh AT people who are struggling.

And he gets the Inigo Montoya principle. (I'm straight-up stealing this from Mandy Patinkin.) The first time Inigo says "Hello, my name is Inigo Montoya. You killed my father. Prepare to die." it's part of the bit. It's...not precisely funny, but it's a part. But as it repeats and crescendos, it stops being funny and captures the character arc. And the payoff for Inigo at the end - it's perfect and it's perfect because the joke becomes the story becomes the resolution.
Hall does that with Paris, with his mental health struggles. It's told with less humor each time until it becomes the moment you are waiting for and crescendos and it works because Hall took you through the experience. 
Not that I would expect anything less from Hall, but A+ realistic portrayal of mental illness in relationships.

Reading this book was complicated, given that I am, well, an overeducated and underselfesteemed person myself. Paris's spirals and self-sabotaging behavior were hard to read because they were achingly familiar. (It's super fun when your empathy for other people is off but by god do you feel things that happen to fictional characters.) I loved it and I loved it because it felt simultaneously absurd and too real and I had to put it down multiple times and cover my eyes and then pick it right up again because I had to know, damn it.

And I made it this far through without talking about Tariq and how much his portrayal as someone adamant about being both queer and religious and not fitting in in either space felt incredibly real and a gift to see the people I know who walk that walk daily so accurately depicted in media. 
Ugh, everything about this book.