Passcodes
Below you'll find passcodes that you'll normally gain after defeating a stage boss. Each one has a description of what bosses have been defeated and how many items X will have.
| 8 | 8 | 4 | 3 | Bosses defeated: None |
| 8 | 2 | 8 | 2 | Energy hearts: 0 |
| 3 | 8 | 4 | 1 | Sub-tanks: 0 |
| 4 | 6 | 2 | 6 | Body Upgrades: None Zero's parts: 0 |
| 3 | 8 | 3 | 5 | Bosses defeated: Wire Sponge |
| 8 | 2 | 8 | 6 | Energy hearts: 1 |
| 3 | 8 | 4 | 1 | Sub-tanks: 1 |
| 1 | 4 | 2 | 6 | Body Upgrades: None Zero's parts: 0 |
| 5 | 5 | 3 | 3 | Bosses defeated: Wire Sponge, Wheel Gator |
| 6 | 8 | 8 | 5 | Energy hearts: 1 |
| 3 | 7 | 8 | 1 | Sub-tanks: 1 |
| 1 | 2 | 5 | 1 | Body Upgrades: None Zero's parts: 0 |
| 8 | 5 | 2 | 8 | Bosses defeated: Wire Sponge, Wheel Gator, Flame Stag |
| 1 | 2 | 8 | 3 | Energy hearts: 2 |
| 3 | 8 | 6 | 4 | Sub-tanks: 2 |
| 1 | 3 | 2 | 3 | Body Upgrades: None Zero's parts: 1 |
| 7 | 6 | 3 | 4 | Bosses defeated: Wire Sponge, Wheel Gator, Flame Stag, Morph Moth |
| 5 | 7 | 3 | 6 | Energy hearts: 2 |
| 3 | 1 | 2 | 4 | Sub-tanks: 2 |
| 7 | 2 | 4 | 6 | Body Upgrades: Armor Zero's parts: 2 |
| 7 | 6 | 5 | 4 | Bosses defeated: Wire Sponge, Wheel Gator, Flame Stag, Morph Moth, Magna Centipede |
| 7 | 2 | 7 | 6 | Energy hearts: 2 |
| 3 | 4 | 2 | 4 | Sub-tanks: 2 |
| 7 | 5 | 3 | 3 | Body Upgrades: Armor Zero's parts: 3 |
| 4 | 7 | 6 | 6 | Bosses defeated: Wire Sponge, Wheel Gator, Flame Stag, Morph Moth, Magna Centipede, Crystal Snail |
| 3 | 8 | 1 | 5 | Energy hearts: 3 |
| 3 | 3 | 8 | 4 | Sub-tanks: 2 |
| 3 | 6 | 5 | 1 | Body Upgrades: Armor, Helmet Zero's parts: 3 |
| 5 | 3 | 5 | 7 | Bosses defeated: Wire Sponge, Wheel Gator, Flame Stag, Morph Moth, Magna Centipede, Crystal Snail, Overdrive Ostrich |
| 6 | 8 | 4 | 5 | Energy hearts: 5 |
| 3 | 8 | 2 | 8 | Sub-tanks: 2 |
| 7 | 4 | 8 | 1 | Body Upgrades: Armor, Helmet, Boots Zero's parts: 3 |
| 6 | 4 | 7 | 4 | Bosses defeated: Wire Sponge, Wheel Gator, Flame Stag, Morph Moth, Magna Centipede, Crystal Snail, Overdrive Ostrich, Bubble Crab |
| 6 | 3 | 4 | 7 | Energy hearts: 8 |
| 6 | 7 | 2 | 8 | Sub-tanks: 4 |
| 7 | 2 | 2 | 6 | Body Upgrades: Armor, Helmet, Boots, X-Buster Zero's parts: 3 |