So, something I’ve been mulling over that turned into a bit of an essay…
One of the innovations of The Witness that I most admired is its fully knowledge-based metrovania structure. You can access almost the whole island from the beginning, but areas are gated behind mysterious, complex puzzles whose rules you cannot hope to deduce. In order to progress, you must find “tutorial panel series” that demonstrate rules from the ground up. It’s a brilliant solution to both lock-and-key structure and player training (making each tutorial a prize you’re pleased to discover, instead of a chore).
This feels satisfying and fresh partly because the traditional Metrovania structure has become ossified – some have even degenerated into a thin papering over of a linear structure. An example offender is Axiom Verge, which largely has the structure of single-path-traversable with one barrier visible to an unreachable area -> powerup lets you reach that area, rinse repeat. Another is Zero Mission, by far my least favorite Metroid (at least Fusion was relatively honest about its linearity).
So I’ve long felt that sequence breaking, or at least the possibility of it, is key to a great Metrovania. Sequence breaking is typically associated with glitches: the clever or accidental defeat of the designer’s intent. Axiom Verge was trying to draw on that mysterious, sinister vitality of glitches with its “glitch”-themed powerups. But it felt hollow when they amounted to ordinary weapon and movement abilities.
At first my reaction to Axiom Verge’s failure was that the problem is fundamental – it must be impossible by definition for a game designer to intentionally introduce a sequence break. But lately I’ve been thinking the most important aspect is not the thrill of rebellion, but the fact that it’s a soft knowledge or skill barrier rather than a rigid lock-and-key. For example, Spelunky’s ball-and-chain-based trick to carry an eggplant into Hell became no less satisfying when the devs promoted that interaction from glitch to officially supported mechanic (fixing the artwork but not the behavior). Likewise, Dark Souls’s Master Key sequence break – literally based on a key – is completely unsatisfying, whereas attempting to rush through Catacombs or New Londo, enemy immortality be damned, is very satisfying.
Another essential part of the appeal of glitches (sequence break or not) is the impression that the game is made out of laws of nature, interacting emergently together, and that these laws are deeper and higher than some designer’s narrative arrow of destiny. This order of precedence is in better tune with our 21st century understanding of how the real world operates (Newton > Hegel, we mostly agree), which Derek Yu calls in his Spelunky book indifference. And this connection between glitches and scientism comes back to a theme of The Witness.
So, as for this thread's title. Thanks to its complex movement physics, Super Metroid is known for its great variety of glitch-based sequence breaks -- including "machball", "short charge", "gravity jump", "CWJ", and "ice clip" (non-exhaustive list). Not only can you sequence break in SM, each given gate typically has at least two ways to glitch through it. So Super Metroid's legendary sequence-breakability appears to be an accident of coding. In part there's no doubt that's true -- missile doors, wrecked ship moat, and Lower Norfair entrance were definitely intended to be completely impassable, among others.
However, that can’t be the whole story – infinite bomb jumping is actually demonstrated in the title screen demo reel, which the devs couldn’t have failed to realize allows sequence breaking. In general the open plan and almost-reachable placement of many gates tells me the designers wanted to at least tantalize players with the possibility of sequence breaking, and were tolerant of the possibility that some might even succeed. What’s more, I realized that the famous cute “animals”, best known for being optionally rescuable after beating the final boss, are very close to an instance of The Witness’s knowledge-based lock-and-key, right there in the genre’s prototypical game. The main reason the animals are in the game is to teach the player how to wall jump and how to shinespark, two mechanics which do unlock additional areas (albeit, mostly optional ones).
Another way of phrasing it is that Super Metroid’s guiding principle is the player’s gradual discovery and mastery of Samus’s powers – with new areas to explore as the reward – and this was conceived to emerge from not only powerups, but also the discovery of secret mechanics that were there all along. So I might go so far as to claim that those “Animals” have been the hidden key to what makes this genre compelling all along.