Ever since Mario first defied every natural law of physics only to be told that the Princess was, in fact, actually chilling in some other dude's castle (and lol, sure she was), video games have absolutely reveled in the old rug pull. Friends become enemies, enemies become friends, the cake - of all things - is a lie, you've played them.
Traditionally the seeds of these things tend to be woven into the story from the very start and, sadly, once you've been around the block and/or assorted castles a few times you get fairly accustomed to spotting them. It's pretty rare that any title is able to hide an absolute gamechanger from you, let alone something that recontextualizes the entire narrative.
Rarer still though, is the whole idea of not revealing your biggest twists. Instead, going to lengths to insert them into the game but happily letting the majority of players ride through without ever spotting them. Whether that's having NPCs with astonishing but optional scenes, or just writing an entire subplot into a new character, shoving them into the background, and never mentioning them again.
10. Moira And Patrick - Bioshock
For a large part of Bioshock, Moira and Patrick provide the proof of both Andrew Ryan's inherent evil, and Atlas's noble intentions. Being, as they are, the supposed wife and child of the latter, who are horrifically blown up in a submarine while attempting to escape Rapture.
With several unidentifiable bodies (mostly Splicers) splattered all over Smuggler's Hideout, Atlas falls into a relatively convincing state of grief and implores the player to seek Ryan out and enact some semblance of revenge. I mean, come on! The man's family was in that submarine!! Why wouldn't you go and crack some skulls!!! Ey!?!?
However, if you've been paying attention, you'll notice that the names Patrick and Moira are plastered everywhere in the game. It's the title of a musical about some dead people at the Fleet Hall Theatre, and my word what a coincidence that must be.
Oops nope, you've just been played. Dropping the Atlas moniker, Frank Fontaine reveals it was all a ruse to have you do his bidding, even joking that he might have to get a real family one day as they "play well with the suckers". That's you.