The first time played Super Metroid, it was after I played Fusion and Zero Mission, and I was actually rather unimpressed by it, despite it being basically a platinum standard for 2D metroidvanias.

It was only later, after playing various romhacks including randomizers and getting much more accustomed to the game engine and the sheer number of possibilities afforded by various speed tricks and sequence-breaking techniques, that I gradually realized why it's held in such high regard. The game is...neat, if you simply play through it once. But the more you learn about it the more you can do with it and the more fascinating it becomes. There is a seemingly infinite depth to it, which is not at all obvious on a first playthrough. In fact, some of it appears to be accidental, possibly game design bugs on the programmers' part, yet somehow such imperfects have made it even more of a masterpiece.