Metroid (1986/87) felt like nothing else on the system — lonely, eerie, and open. No hand-holding, no straight line; just the alien depths of Zebes and a series of locked doors waiting for an upgrade you hadn't found yet.

It's half the namesake of the entire "Metroidvania" genre: explore, hit a wall, find the morph ball or the missiles, double back, open the world a little wider. The password system stood in for saves, and trading codes was its own playground ride.

And of course — finish it fast enough and the armored bounty hunter Samus Aran takes off the helmet. In 1986, that reveal landed like a thunderclap. The atmosphere is what stuck with me: cold, quiet, and a little bit scary.