The first Pirates of the Caribbean was a solid movie. Clear plot, memorable characters. And the antics and double-crossing one would expect from a Disney film about pirates starring Johnny Depp.
The second Pirates movie, Dead Man's Chest, was also good. But, it started to get confusing. More subplots, more double-crossing and shifting allegiances. But all in all, a decent movie.
And then there was the third Pirates movie, At World's End. Wrapping up the trilogy, the third film had so many deals, subplots, double crosses, changing allegiances, and shifting storylines, only the most diehard of fans could really tell you what the movie was about.
When we have a good thing in creative work, it's possible to go overboard.
The key is to figure out at what point you start losing the audience.