From their colorful, E-rated franchises to their "easy to learn and difficult to master" game mechanics, Nintendo has been known for making video games accessible to all kinds of people. A prime example is their mustachioed mascot Mario's eponymous Super Mario game series and its progression gameplay. Progression gameplay is a model of gameplay that refers to how the game designers sets certain required courses of action that enable players to advance in the game. In the Super Mario series, the progression gameplay tends to leave required challenges relatively straightforward and reward higher skill-level puzzle-platforming with optional collectibles (e.g. red coins in Super Mario 64, blue coins in Super Mario Sunshine, and so forth). The player, then, is able to complete the main storyline in basically every Super Mario game without completing the game's most difficult platforming challenges.
But if we look at the progression gameplay in Jonathan Blow's Braid (2008), a puzzle-platformer that unquestionably references the Super Mario series in more than one way, an interesting contrast comes up. Worlds 2 through 6 in Braid contain 12 puzzle pieces each, spread out across the world's 4 to 8 levels. Although collecting each puzzle piece is not necessary to progress between worlds, the player must collect every puzzle piece (and arrange the puzzle pieces into 5 respective images) in order to advance to World 1 (the final world) and the epilogue. The puzzle pieces, aptly named, test the player's mastery of the controls and game mechanics, rewarding only a narrow set of solutions. But digging further, this means these puzzle pieces also test the player on traits they may not have so much control over: motor skills, reaction time, visual acuity, intelligence, and so forth. And the puzzles become more and more complex and difficult as the game progresses. With increasing difficulty level being an intrinsic part of a games progression gameplay, one must question how accessible the game is: What kinds of people are rewarded the most in playing the game? What kinds of people does the game marginalize? How do these gates play into the meaning of the game? I don't argue that every game should be accessible to as wide-reaching an audience of people, but when the game itself narrows that audience, it's worth looking closely at.
In setting its 60 puzzle pieces as a prerequisite for access to the game's narrative climax, Braid privileges certain audiences to its narrative. With its narrative themes of scientific knowledge and discovery as part of the narrative, one could argue that Braid is aware of the way it privileges certain audiences. If the protagonist Tim's failing flaws are his hubris and lust for knowledge, this makes sense: Braid's progression gameplay selects players to embody Tim's flaws. Collecting all 60 puzzle pieces involves exploiting and killing Monstars (waddling Goomba look-alikes), Mimics (flower-bunny creatures), and even an alternate version of Tim's self for this pursuit of something between knowledge and conquest. Only players who have completed this selection examination sorts may advance to the final chapters of Braid, where the themes and meanings of the narrative unfold and reveal themselves most explicitly, arguably the most pivotal moments of the game's narrative. Players who fail to complete the games' puzzles for whatever reason—they're not clever enough, they're not curious enough, they give up, or they get bored—are not granted access.
But of course, we're talking about 2008, not 1988. Online walkthroughs and Let's Plays are about as available as Starbucks and McDonald's, so supposedly anyone can complete the game if they really wanted to. Except that comes at a cost: not only does looking up solutions take away from the Ah-ha! experience of discovering solutions on your own, gamers often shame other gamers for lacking the skills, expertise, or even intelligence necessary to play games the "right" way. Take the abundance of gamer slang pejoratives like "noob," "git gud," and "scrub" that are used to demean players for playing unskillfully. Or look at gatekeeping and shaming among gamers for playing games on insufficiently challenging difficulty levels. The display, proof, and celebration of expertise, mastery, and—ultimately—ability is a theme that pervades video gaming from the games themselves to gamer communities. It's always worth asking who gets a seat at the table—or, here, who gets to be Player 1.
Your post about the differences between Braid and Super Mario are certainly notable, because, as you mentioned, there are very clear references to it (and other platformer classics as well). However, my interpretation of it was to showcase the difference. While collectibles in most games were just that, collectibles, the necessity of the puzzle pieces ended up having so much more meaning in gathering it versus the coins in Mario. This is just one of many ways Braid subverts the platformer tropes, from the lack of checkpoints and lives to the whole mechanic of reversing one's mistakes.
You mentioned about how this change purposely limits the audience, and to that I agree. But I also believe that is precisely what…