>>719755543
Semi-marked secret: ambiguous tiling
Thanks to its improved graphical possibilities, Super Metroid pushed a lot the serie's secret design, by incorporating more natural-looking breakable elements. Due to the variety of the tiles, it could also hint at a secret without being as explicit as >>719755124 old games. By making and breaking patterns in the walls, they could also put red herrings. This pushes the player to check everything suspicious and make a mental model of the developer's habits.
Once you know how the dev designs, a form of communication happens, a discussion where sometimes the developer starts a sentence (places a hint) and the player finishes it (finds the secret on the first try without testing every wall).