Can you base a film review without watching the whole film?

[CitizenSnips]

I remember reading an article on AVClub.com about some Anne Hathaway thriller, can't remember what it was called. But it was explaining how the whole film was basically a set up for the twist - which was itself not too bad, but didn't make up for the awfulness of the film before it.

It makes me wonder though, there might be a film that's kinda boring but whose ending is such a revelation that it rewards a second viewing and sheds new light on everything you see. Theoretically possible, but I don't think such a film exists atm.