I have been playing Metroid games (primarily Super) for a good chunk of my life.
I started playing the original Metroid tonight (well, REALLY playing it and wanting to beat it). Nothing weird happened for the majority of my playthrough until I got to Kraid's Lair.
I entered the first hatch on the right and as the hatch closed, I got knocked back through the doorway by a flyer (I don't know the actual name of the enemy. Or any of the "enemies" in Metroid)
For some reason, this caused the hatch on that doorway to disappear completely. As you will see in the video, I tried going through different hatches, even took the lift to Brinstar and back and still the hatch was missing.
Despite my confusion, I also recognized potential good use of the glitch.
I don't know whether this is a known glitch or not, but considering that this game has been out for thirty-three years I wouldn't doubt that other people have seen this first hand aswell.
If need be at all, this glitch could lessen the amount of time it usually takes to go through a doorway a little bit.
Or maybe not, watching MetroidMcFly's playthrough shows me that people can get through hatches pretty quickly. I haven't finished my playthrough, but perhaps there are harder areas in this game where a hatch stuck open could easily allow someone to make it out of a hard to deal with room.
[youtube]NoraAQx3Ggs[/youtube]
Missile doors stay open once you open them the first time, it’s not a glitch as far as I know. They only close after you from super Metroid onwards.
