It's you against the evil Mother Brain in the thrilling battle of Metroid! You're inside the fortress planet Zebes. The planet of endless secret passageways where the Metroid are multiplying. Left alone the Metroid are harmless. But in the wrong hands they could destroy the galaxy. It's up to you to prevent the Mother Brain that controls Zebes from using the Metroid for evil purposes. But that won't be easy. You'll have to use your spacesuit to absorb valuable energy for your search to gain the use of power items like the Ice Beam, Wave Beam, High Jump Boots and Varia. If you survive, it will be you and your acquired powers against the Mother Brain.

Straight from the readme:

..WHAT IS IT?..
This is a hack that turns the NES game Metroid into a Bionic Commando-themed
game by changing some graphics and text. (hey, remember to read the opening
text!)

Storyline: Mother Brain and the Space Pirates have stolen the Bionic Arm
technology! They intend to develop an army of bionic creatures to take
over the universe. Oh, and they also kidnapped Samus. So Rad has to
travel to their planet to set things right before it's too late. Since
they stole his bionic arm, he'll have to learn to get around without it..
but at least now he can jump freely. So go for it! If you quickly rescue
Samus (beat the game in a certain ammount of time), she might reward you
by doing a strip-tease! :)

Metroid (USA) - NOINTRO
CRC32: A2C89CB9
MD5: D77C8053168DA14B360BF5CAECCC5964
SHA-1: ECF39EC5A33E6A6F832F03E8FFC61C5D53F4F90B
SHA-256: E6E6B7014685ADAE447EBB3833242815747BC1E5DF83ADE79F693FB67CF565B6