This movie is all about the dialogue and the acting, and both are excellent. Very little happens other than two characters talking honestly, intelligently, and naturally with each other, and so the success of the entire film rests on the audience being interested in the conversation, and liking the characters enough to stick with them. I did.
The film kept my attention throughout, and was nicely photographed and edited, without reinventing the wheel or distracting with needless artsy-fartsy imagery. A simple story, simply told.
A note on the Netflix certificate: Netflix displays an 18 certificate with the warning "strong sex". This is patently absurd, since the two or three sex scenes in the film are very tame, showing nothing more than bare male chests and legs, and maybe a brief glimpse of thigh. Clearly it's the fact that the sex scenes involve two men that makes it so "strong" - and in this day and age I find that double standard offensive. If the same scenes had featured a heterosexual couple, they would have been PG or at a push PG13 and described as "mild". Times and attitudes are changing, but clearly not fast enough.