No it was also the design. Bioshock mechanically was very unique at the time of release with it's powers and weapon switching. Uncharted 2 was unique because we were seeing set pieces that weren't thought to be possible at all. The train sections, the building collapsing, the set pieces in general were mind blowing. The presentation of the narratives only served to enhance these things. Walking Dead was incredibly effective as a game because of the great writing and ofc the choices it let you made which in the moment were intense and felt more personal and you wanted to see the story unfold, it was very unique at the time despite other games having more "gameplay."
you know it's funny that i pointed out those four platformers and you didn't really see a difference. i'm a platformer fan and i
know the differences between them. nsmb isn't very good. it was critically well-received upon release, but fans weren't big on it. the game is a pretty rote 2d mario game that hangs a pretty crummy shadow over the much better iterations of the nsmb games that followed. it's mostly a left-to-right platformer with not a lot going for it. braid is a puzzle-platformer that uses the time travel mechanic to solve puzzles and create platforms in creative ways. super meat boy is a frustration platformer, where the game produces a lot of small challenges that are very difficult but satisfying to complete. rayman legends is closer to new super mario bros., but with multiplayer, more verticality, and a lot of forced-running levels.
but you saw four platformers and saw them as pretty much the same thing. that's kind of what i'm getting at.
i was around for each one of the games that you mentioned. i even bought a 360 in part to play bioshock. what i remember people speaking most of was about how you had to choose between being mega hitler or
not a child murderer, while the main story was really actually making you go through the main story the whole time - what a twist! uncharted 2 is naughty dog not understanding what makes an underdog fun or an everyman work. i liked it enough, but i much preferred actually climbing the buildings and locations than running from their destruction. it just felt like more skill was involved (that's nothing to say of how it wasn't done earlier with beyond good & evil, but i don't think naughty dog people were actually inspired by the works of the cosmic deity, michel ancel). choices actually don't matter in walking dead. the story happens one way whether you think it should go one way or not. it would have been more effective to make it like back to the future: the game, with more puzzles. there's absolutely nothing unique about this game when it came after 999, mass effect 1-3, kotor 1 and 2, basically every other western rpg where they pretend choosing things makes a difference, basically every other game where they pretend choosing things makes a difference.
they're all connected by drama. maybe uncharted 2 to a lesser extent (it's pretty dramatic but i think people remember it more for being exciting), and the dramatic moments that happened in them. i want to bring up the last of us because i think it's a good counterpoint to a lot of these games. you have the standard relationship with joel and ellie, as well as a gameplay mechanic where ellie basically learns from joel how to incapacitate people. this is a passive thing and it's never outright stated to the player. joel also lives in a really violent post-apocalyptic world where it's every man for himself. it makes sense here that he and the people around him would be fucking brutal. the world is littered with trash and parts of an older time - this can lead to new equipment and improved equipment because joel needs to scavenge to survive. there's also notes and other artifacts from the time before the outbreak, and during and after, that helps flesh out the world more. this stuff can be missed, but it's up to the player to decide how much they want to search the world for it. and it all just works together. the story and the gameplay and the world all work as a whole.
and the last of us is also dramatic. it's also serious. i think the story, which perhaps the best on the list, is what earns it the top spot though. i don't know if there's as much appreciation paid to how it all came together and functioned. although on the other hand, maybe gone home would have won instead if there was.