The phenomenon of people being disgruntled that they already knew the major twist(s) of a piece of media before viewing it, not considering that the twist wasn’t intended for the audience, but the characters. Basically, just because it doesn't happen until part or most of the way in doesn't mean that it's a bad thing to know. In fact, it can be a good thing to know that the idyllic village will be blown apart so you don't drag your 5 year old into the theater (though that doesn't stop some people...) It's important to have the basic plot outlined so potential audiences know it's the kind of movie they want to see and avoid Trailers Always Lie.
Hello, Unknown Troper. You'll need to get known to lend a hand here.