Unlock Hyper Mode Difficulty
Beat the game and you will get Hyper Mode Difficulty.

100% Ending
Collect all 100 pickups to view a secret ending clip after the game credits.

Reveal all item locations
Go to the place in Skytown when you have to get the first part of the bomb you have to make using your ship. 
Near the bottom there is some Phazite, shoot the switch inside to activate the satelite system. 
Go to the top and go around the walls using the spiderball tracks and bomb all the bomb slots 
to get markers on your map for where every expansion(missle,ship missle,and E tanks) is in every part of the game, 
except the items that are in the Valhalla.

Unlock Music
The content below is unlockable in the game. You must use credits earned in the game (of all four varieties) to unlock anything. 
Listed next to each piece of unlockable content is the number of each credits you\'ll need 
to unlock said content. B = Blue Credits, F = Friend Credits, G = Gold Credits, and R = Red Credits.

Battle Theme (GF) - 2B/0F/1G/4R
Battle Theme (Metroid) - 2B/0F/1G/4R
Gandrayda - 2B/0F/1G/4R
Gryyo - 2B/0F/1G/4RM
Gryyo (Thorn Jungle) - 2B/0F/1G/4R
Helios - 2B/0F/1G/4R
In the Cockpit - 2B/0F/1G/4R
Omega Ridley - 2B/0F/1G/4R
Phaaze - 2B/0F/1G/4R
Pirate Homeworld - 2B/0F/1G/4R
Skytown - 2B/0F/1G/4R
Steamlord - 2B/0F/1G/4R
The Corruption - 2B/0F/1G/4R
Title Screen - 2B/0F/1G/4R
Valhalla - 2B/0F/1G/4R

Unlock Extra Content
The content below is unlockable in the game. You must use credits earned in the game (of all four varieties) to unlock anything. 
Listed next to each piece of unlockable content is the number of each credits you\'ll need 
to unlock said content. B = Blue Credits, F = Friend Credits, G = Gold Credits, and R = Red Credits.

Bumper Stickers - 1B/2F/3G/3R
Diorama (I) - 1B/1F/3G/3R
Diorama (II) - 1B/1F/3G/3R
Diorama (III) - 1B/1F/3G/3R
Diorama (IV) - 1B/1F/3G/3R
Diorama (V) - 1B/1F/3G/3R
Diorama (VI) - 1B/1F/3G/3R
Mii Bobblehead - 1B/2F/3G/3R
Screenshot Taker - 1B/2F/3G/3R

Secret Message from Iwata
When in Samus\' ship, go to the radio And press the following symbols. 
Going from left to right, press the second symbol, the seventh symbol, the fifth symbol 
and then the first symbol. You\'ll be greeted by Iwata himself. Of course, this is in Japanese.

A brief translation: \"Hello, this is Iwata from Nintendo. 
A president has to take things really seriously, even if it doesn\'t seem like it. 
It\'s understandable if you lose weight from stress...but I get fatter instead. Nobody thinks I\'m taking it seriously.\"

Secret Message from Miyamoto
When in Samus\' ship, go to the radio and press the following symbols (from left to right): 
the eighth symbol, the third symbol, the fifth symbol and then the fourth symbol. 
You will then hear a message from Mr. Miyamoto!

A rough translation: \"Ah, can you hear me? This is Miyamoto. 
All of you playing Metroid, can you hear me? It\'s fun, isn\'t it? 
I\'ve also worked on many [Metroid] games, but this one is the best yet, don\'t you think? 
Definitely play it all the way to the end. See you!\"

Secret Message from Yoshio Sakamoto
When in Samus\' ship, go to the radio and press the following symbols: 
Going from left to right, press the fourth symbol, the sixth symbol, the first symbol and then the seventh symbol. 
You will then hear a message from Mr. Sakamoto, co-creator of the Metroid Series!

Get Friend Vouchers Quickly
You can get a friend voucher for performing certain tasks that you can trade with other players who have the game. 
Once traded, these can be used for buying special extras. 
Among other things, you get a voucher for every 100 kills (up to 1,000). 
An easy way to rake in 10 vouchers is to look for swarms of small, explosive bugs that crawl around the levels 
after the Space Pirates attack. Just sit there and zap \'em and you can get to 1,000 kills fairly quickly.

Friend Credit Tips
Bowling for Bots: In Skytown, if you use Morph Ball to run over the Tinbots, you\'ll gain this bonus. 
Easiest place to do this is in the doughnut-shaped room.

Stylish Kill: In Skytown, there\'s a Bridge area that collapses when you cross it. 
Before it falls, there\'s a fight with Tinbots and the Master Bot. Ignore them and finish crossing the bridge. 
A cutscene with go off and show the bot fall to their doom.

Killing Helios
To kill Helios easily, fire at the open spots on his body until he reveals his Phazon center. 
When he does this, quickly go into Hyper Mode, and then into Morph Ball mode, and attack him quickly for an easy kill.

Stop The Boss
When Aurora Unit 313 is on the ground and spinning around, you can use the Screw Attack to stun it.