Even in the climax of his superhero movie trilogy, which took him nearly two decades to complete, M. Night Shyamalan had to add one last twist. The director, who is divisive among critics and audiences alike, has made shock revelations in the final minutes of his movies his signature ever since his 1999 breakout hit The Sixth Sense. Shyamalan and surprise endings are like peanut butter and jelly or Oreos and milk. The twists tend to fall into three general categories. There are the effective ones that also have the benefit of being bolstered by characters and a story that make repeated viewings a rewarding experience. The best example of that is the revelation at the end of Sixth Sense. Then there are the ones that just sort of sputter out, like the climax of Signs. Finally, there are the ones that not only disappoint after the initial viewing but collapse completely when you apply any scrutiny at all. The ludicrous ending to The Village fits here.
Having only seen Glass once, I’ll classify its surprise ending as a mix of the first and last categories, although it will probably hold up fairly well on repeat viewings.