>>719756172
This was also the game that introduced X-ray vision, which for me was slightly a detriment to secret design as the Dev could possibly count on that as a crutch to design complicated patterns that do not rely on the player's investigative abilities to find. Thanksfully I think the devs limited the amount of "mean" secrets and the game is playable without over-using the X-ray, which also felt burdensome to use (slow aim, stops you in your tracks).

Also not recorded but Super Metroid has one short loop section that you cannot escape without finding a secret wall to pass trough, that is unmarked and doesn't show on X-ray. The idea is that since you are emprissoned in a closed limited space, you will eventually find the right wall to exit trough. This design technique will be expanded upon and improved in Fusion.