Hidden content is par for the course when it comes to video games. When developers spend years working on projects, they're prone to leaving little personal touches in all sorts of places, whether they manifest as simple throwaway bits of text, a hidden image or occasionally entire levels and cutscenes tucked away in the furthest reaches of the game's code.
However sometimes content is cut, hidden and otherwise buried so deeply that you’d be forgiven for thinking that no one was actually meant to ever find it. Of course, while achieving that level of secrecy might have been possible back when some of these titles initially released, in 2018, with the internet readily available, nothing stays hidden for long, as players obsess over details and mine a title's code for every possible detail.
Whether they were vital parts of the story (such as Metal Gear Solid V's fabled third chapter) or simply funny jokes developers slipped into their projects, there have been plenty of detailed cutscenes included in games that the majority of players would never, ever see.