Expectations increase with each new building block to the structure, so that the whole does not collapse. This is true when an author, or even a musician to a series of albums, or a screenwriter, a playwright, a game developing company, and others, consider how they are going to top their last piece. The entire point of a sequel is not to have a new idea. It is to have bettered the last piece, in every way possible. The newness and originality are always secondary.
For sequels, one has to advance past the last idea, of the same sequence. Expectations raise, much like how a skyscraper is built, for a sequel seems to much like post-modernism. It advances for the simple sake of advancing. New ideas are broken down, in favor of the universal through a singular perspective.
Expectations are always immense for something that should not ever collapse, such as a skyscraper. We stare upwards at those tall monoliths, wondering if they’ll ever fall. 9/11 has proved it to be possible, resulting not only in the collapse of the buildings, though also the following recession.
Sequels are unneeded, when you could simply have a new idea, a blank slate, a fresh mind, without fear of collapse.
The true issue with sequels is when the next piece in the sequence of pieces is seen to be a disappointment, one cannot tell if the series is building upwards or building downwards. It merely comes down to one’s “perspective” of the matter, despite how our only “perspective” was to stare up at its rising.