Released in August 1987 in USA.
The greatest difference between the original Japanese version and this version is the saving option. Instead of writing down a password, Japanese players could save their progress in one of the three available save slots on the disk. Another interesting element present in the original version (and never included in the cartridge game) are the creepy sound effects that some of the Metroids do. Thanks to the improved sound chip integrated with the Famicom Disk System, some of them sound much more organic than the electronic 'beeps' from this version.
Mistranslation: In the opening story, the planet Zebes is referred to as 'Zebeth'. This is due to a mistranslation from Japanese to English. In Japan, the 'S' sound and the 'TH' sound are interchangeable.
* Passwords :
M7---- --zOA0 2T-tfm a000d5 (Tourian)
00U--- -u0000 0AFw9Y 1800sb (Hideout 2)
022400 A00000 05?00m 0000aS (Brinstar with Screw Ball and Ice Beam)
0WX002 W00004 1VW0C0 0000MO (Q2 Brinstar with Screw Attack, Ice Beam and Leotard Samus)
Daniel Daniel Daniel Daniel (Norfair with no bombs)
XXXXXX XXXXXX KKKKKK KKKKKK (Tourian with weak weapons and Leotard Samus - impossible)
JUSTIN BAILEY ------ ------ (Norfair with Wave Beam, Long Beam, Bomb, Jump Boots, Varia, Screw Attack 5 Tanks, 205 Missiles and Leotard Samus)
JUSTIN BAILEY ------ 000000 (Hideout 2 with Ice Beam, Long Beam, Bomb, Jump Boots, Varia, Screw Attack, 5 Tanks, 255 Missiles and Leotard Samus)
justin bailey ------ ------ (Reset to title screen)
BOMBS- Missile SCREW- ATACK- (111 missiles, Ice Beam, Bombs and 4 energy tanks)
KIDICA RUSc19 86NINT ENDO-- (Hideout 1, Ice Beam, Screw Attack, 4 Tanks and 42 Missiles)
999999 999999 KKKKKK KKKKKK (Hideout 2, no Kraid, no Varia, no Mother Brain, no final time limit)
X-z-uJ lls0W0 fVvweG 000WNr (215 missiles, 5 energy tanks, all powerups, both mini-bosses dead)
000000 000000 03-200 000089 (255 missiles, but no missile tanks)
000000 000000 080h00 0000gu (Begin with missiles but no missiles in Kraid's lair)
000000 000001 00F300 00008X (Begin with missiles, but no missile tanks in Ridley's lair)
X----- --N?WO dV-Gm9 W01GMI (see Metroid's best ending)
F2-yum akMKa0 O2-oKm 0000fr (Get Ice Beam)
000800 000000 02080H e000?q (Get Long Beam)
mMuiS1 II6-GE Jls?h0 m00WRM (No suit and All Weapons)
00WX00 2W0000 41TW1o 0000LD (Play with Samus with her suit off!)
00U--- -u0000 0AFw9Y 1800sb (Go to Rifley)
C00000 000000 080h00 00006u (Begin with bombs)
NARPAS SWORD0 000000 000000 (infinite health, missiles, Ice Beam, all power-up with the exception of Energy Tanks, Missile Expansions and the Wave Beam.