As video game trailers have become more lovingly made and often cinematic rather than reflective of actual in-game content, there’s been a growing disconnect between the game we think we’re getting from the trailer and the game that actually comes out.
This got particularly bad around five to ten years ago and there’s since been a consumer backlash that’s resulted in studios often adding a watermark to their trailers or demos to tell you whether they’re cinematic or depicting in-engine footage.
Even though things are arguably getting better, it was still a seminal point in time when gamers had to learn a hard lesson not to judge a game by its trailer. This isn’t to say the problem is entirely fixed as of 2021, but you’ll recognise a lot of these titles from a handful of years back.
I should say that though all these trailers led us astray, that doesn't mean the games that came out of them were necessarily bad. Unless you’re talking Aliens: Colonial Marines. Then it’s bad.