I enjoyed an intriguing and thought-provoking first 2/3rds, but this film was badly let down by a disjointed and unsatisfying final third.
To summarise, see this exerpt from a four star review:
"I'm Thinking of Ending Things is very heady; the kind of movie you have to watch a bunch of times or read a lot about to understand. You can tell something is off, but won't really know what's going on while you're watching it . It's confusing. Slow but intriguing. It was like watching a weird dream"