If a trailer is longer than 30 seconds it is bad. Full stop. There is too much given away.

Also the Prometheus trailer was more than terrible, possibly the single worst trailer in the last decade, maybe ever, because it gave away the entire movie. How it made it to this list is beyond my imagination, which is grotesquely large, but full disclosure I didn’t read the section about it so I just hope you used it as an example of exactly what not to do.