Original NES Metroid Game
Complete one run through Metroid: Zero Mission.

All Zero Mission Endings
To open up the various game endings fulfill these requirements.

    * Samus in shorts, at a bar: Complete the game in under two hours on Normal with 100%.
    * Samus in shorts, in a city: Complete the game in over two hours on Normal or Hard with 100%.
    * Samus on a rock: Complete the game on Easy, or complete the game in over four hours in Normal or Hard with more than 15%.
    * Samus in a blue jumpsuit: Complete the game in under two hours on Normal or Hard with more than 15%.
    * Samus in shorts, looking over a city: Complete the game in under two hours on Hard with 100%.
    * Samus in shorts, looking out a window: Complete the game on Normal with less than 15%.
    * Samus with a close up on her face without armor: Complete the game on Hard with less than 15%.
    * Samus without helmet, looking at a sunset: Complete the game in three hours on Normal or Hard with more than 15%. 

Time Attack Mode
Beat Zero Mission once through and begin a new game with the completed save file. View the timer on the map screen.

Unlockables

    * Fusion Gallery: Link up with Metroid Fusion
    * Gallery: Complete the game once (images will be added when you beat the game differently.
    * Hard Mode: Complete the game once on Normal.
    * Original Metroid: Complete the game once.
    * Sound Test: Complete Hard Mode Once.