It was named #11 out of 200 of the "Greatest Games of Their Time" by EGM Issue #200 (Feb. 2006).
Samus Aran made a regular appearance in the Valiant comic series Captain N: The Game Master, replacing the TV show's regular character line-up of Mega Man and Simon Belmont. Samus would often compete with Princess Lana for Kevin's affections.
The comic series was different as it used only Nintendo licensed characters, and not the 3rd party heroes.
Metroid series was obviously somewhat inspired by the Alien series of films. Among the most visible similarities are tough female protagonist, and icky alien creatures that try to eat your head. Ridley, one of the two mini-bosses in Metroid, was named after Ridley Scott who directed the first Alien movie. The game parallels other elements from the movie as well, including climactic self-destruct countdowns, egg-hatching extraterrestrials, a main antagonist named after Alien's 'Mother' computer, and a female lead character called Samus Aran (in reverence to Alien's Ripley).
Metroid was voted #6 in the Top 100 Games of All Time poll published by Game Informer Magazine (Issue 100, August 2001).
The original japanese release of Metroid was for the Famicom's floppy disk accessory, which used 3/4" floppy disks instead of cartridges and never made it out of Japan. The main difference this added to the game was that the Japanese release used a file-save system while the western releases had to incorporate a password system like on the original Zelda.
The existance of this different version only added to the many urban legends that have always plagued the original Metroid (such as the secret worlds, glitches, etc.) and if I remember correctly this specific info took a major part in giving extra credit to the belief that somehow, somewhere, there was a two-player version of Metroid. Why? Because the box of the US release had a typo that advertised it as a two-player game (check out the original back-cover).
Metroid has 5 endings depending on the time you take to finish it. After the standard "Congratulations" screen Samus would flash, and depending on your final time he would: 1-Raise his hand to you (over 5 hours); 2-Remove his helmet (3-5 hours); And 3- Remove his armor completely and remain in some sort of leotard(less than 3 hours).
Now, the interesting thing happened on those two last endings since Samus revealed his identity, and showed us that he was a woman all along!! This was a major shocker at it's time and a closely guarded secret since at that time these things were very hard to prove and all the documentation referred to him as a He (I personally never believed it until I saw it with my own eyes). So move over Lara! Samus Aran is the original badass babe with a gun.
Furthermore getting the under 3 hrs ending allows you to re-start the game as an armor-less Samus! (just press start after the credits roll) And ending the game this way over 5 hours gets you a different ending where armored Samus just looks away from you in shame.
The fifth and final ending shows Samus without the armor and dressed in nothing but a skimpy bikini! Now that's the kind of reward I want in all my games!! And to unlock it all you have to do is finish the whole game under one hour.... Good f#&ing luck! Just cheat your way to the end with Nesticle or get yourself a very skilled buddy to finish it for you! That's what I did in it's time...