Loved this movie too. Great acting, great cast, good script and directing, made full use of silence and sound editing. Overall 8.5/10. Definitely one of the better movies of the year so far. Worth watching in cinema.

It's not horror per se, thriller monster movie, very nerve wrecking. Also I can't believe Emily Blunt hasn't won an Oscar, the bathtub + nail scenes alone showed her incredible performance. She's really good in conveying these kinds of emotion surge (watch Sicario).

As a whole, John did a great job in directing and acting too. Recommended.

Just a side note about the ending, I too felt it was a bit rushed but I guess, there's not much you can do with movies of this genre. At least it's better than Annihilation.