Metroid is split up between horizontal-scrolling corridors and vertical-scrolling ones. The vertical scrolling ones reach an end when you run into a floor or ceiling. Or do they? No, they don't. So there.

To travel below the floor in Metroid:
You must be able to roll into a ball, and be in a vertical-scrolling corridor that has a blue door. Not too uncommon, right? Shoot open the door and stand over it, then let it close on top of you. Now, quickly alternate pressing down, up, down, up, down, up without stopping. You'll rise through the top of the screen! Then, the screen will start scrolling downwards. You'll reappear at the bottom and move back up to the top. You can keep doing this and see some very long stretches of floor and a few holes and enemies now and then. However, you'll be stuck in the wall - except for one otherwise inaccessable section including a weapon sphere which is unfortunately empty. It's been too long for me to remember where this is, though. Explore and go find it!

A hint -
If you position youself correctly, you'll be able to travel up the wall but still jump out if you want to, and this is what you need to do to get out of some spots. Also, you can stick yourself outside of the "tubes" and into space if you really want to. Also, one place I thought was a secret area, but it was actually just another part of the level, a strange shortcut from a vertical- scrolling section to a horizontal-scrolling section (which confuses the game).

But now for the gigantic secret worlds...
These seem to be some levels that the programmers didn't finish. There are floating doors, corridors without floors, and doors that send you offscreen. If you enter one of these, you should try moving around, sometimes you stumble upon a door and get zapped to another section and are able to see yourself again.

To reach these you need to be able to travel UP past the ceiling. Just do the same trick as before, but before you move past the top of the screen, stop pressing up, down, etc. Make sure the last direction you press is _up_ or you'll stuck as a ball. Now, standing there, start jumping and the screen will scroll upwards. Press down, up, down, up to move up the screen again and repeat! Don't forget, you need to use this trick to move around in some of the worlds...

One definite entrance to a secret world is at the silver corridor with a missle on the left side and an invisible trap you can fall through. This also happens to be the largest of the secret worlds. There are two more, but I've forgotten where they are - I know you reach one by moving to the right right from one of the elevators, the other I totally forget...

Anyways, enjoy! I _dare_ you to try mapping these out! =)

RETURN.VIDGAMES