This is very simple, however some people have problems with the cutscenes skipping because they accidentally hit the A button.
When the loading screen is finished loading, you are prompted to hit any button to continue, press any button but A (I repeat DON’T PRESS A), some people reported that they accidentally hit the A button twice and it causes the cutscene to skip, hence why not a lot of people have this achievement.
This also goes for the dialogue in the game, don’t not skip it cause it counts as a cutscene.
Achievement will unlock before or after the credits. For me it unlocked before the credits started.