The Phazon Combo is an unused Charge Combo for the Phazon Beam in Metroid Prime. In the final game, the Phazon Beam is only usable during the battle against the Metroid Prime's Core Essence when highly concentrated Phazon is available. The beam is also incompatible with the Charge Beam, as holding down A will instead cause continuous fire, although having the upgrade does enable this.
A sound effect of the Phazon Beam charging is present in the game's code [1]. The string table file for the Inventory lists a "Phazon Combo" string, and a fifth Charge Combo slot is present in the enemy vulnerability data. What this Combo would have done is unknown, but the evidence for its existence suggests that the Phazon Beam may have originally had a larger role in the game. Whether the Combo would have been acquired separately or with the Phazon Beam and Suit is also unknown.
| Charge Combos |
|---|
| Super Missile | Wavebuster | Ice Spreader | Flamethrower Darkburst | Sunburst | Sonic Boom Special Charge Beam Attacks | Phazon Combo (unused) |