Beam Weapons
There are five beams you get to control on Metroid Prime.The first is the Power beam, which you have no matter what you do. Hold up on the C stick to trigger this beam.
The second beam is the Wave Beam, which you get for defeating the Sheegoth in Phendrana Drifts. A wave of electricity with three arms runs out of this weapon. Hold right on the C stick to trigger this beam.
The third beam is the Ice Beam, which you get for draining a ramp in the Chozo Ruins. This beam will freeze enemies or just annoy some of them. Hold left on the C stick to trigger this beam.
The fourth beam is the Plasma Beam, which you get for grappling a lot in Magmoor Caverns. My personal favorite. This beam shoots out a blast of fire that will burn an enemy fast. Hold down on the C stick to trigger this beam.
The final beam is the Phazon Beam, which you only get during the Core part of the boss battle against Metroid Prime. You stand in a pile of liquid Phazon and hold A to shoot out an endless (until the pile is gone) beam of Phazon.