What a strange name to give to a weapon that looks like it does very little damage... Anyways, the Annihilator Beam is the last weapon you get after defeating Quadraxis. It shoots pellets of shadow and light energy, and is useful against both types of enemies. It also has a tremendously high rate of fire and can automatically home in on opponents. The downside, you ask? It shoots so fast that you can deplete your ammo in less than half a minute. Every shot takes away 1 ammunition unit from both light and dark. A charged shot shoots out a hyper sonic ball. As far as puzzles, this beam's usefulness is to activate puzzles that require sonic technology (echo visor). This beam can also super energize light crystals/beacon points that lure in Ing enemies and kill them. The charge combo for this is the sonic boom which uses up 30 units of both light and dark beam ammo plus 5 missles but its well worth the price this will completely annihilate (as in the name) anything stupid enough to get hit by it, its fairly slow moving so use it on an enemy that's going to stay in one place for a while.
 Charge Beam
Not really a beam, but a beam upgrade that applies to all beams. It allows you to focus your weapon's energy and shoot a powerful blast. It is also required for Missile Combos. If your low on ammo for a particular weapon and need to open a door charge a shot to fire a regular one.
 Combat Visor
Your Default Visor.
 Dark Beam
The first beam you'll acquire. It roughly has the same rate of fire and speed as the Ice Beam and roughly has the same "freezing" properties. It shoots bursts of concentrated shadow energy. Incredibly useful against light creatures. A charged shot will shoot a burst of dark energy that, once it hits the target, releases shrapnel that will ensnare other enemies close by. Charge shot requires 5 units of dark beam ammo. The Dark Beam also has many uses such as causes objects to retract, shrink, open dark portals or nullifying light crystals. Acquired after beating Dark Samus. The charge combo for the dark beam is the dark burst. Charge it up and shoot a missile and it will open a dimensional rift which will suck in all nearby enemies. Its fairly slow moving so make sure your close when you use it or use it on an enemie thats going to stay in one place for a while. Its costs 30 units of dark beam ammo and 5 missiles.
 Dark Suit
Tremendously slows down the damage done to you by Dark Aether's poisonous environment. Acquired by beating Amorbis in Dark Agon Wastes.
 Dark Visor
The equivalent of the Thermal Visor. Allows you to see enemies and objects that don't appear on the normal spectrum of sight. Useful for fighting cloaked enemies that you normally can't get a lock on.
 Echoes Visor
Let's you see in terms of sound. Required to solve puzzles and detect alternate targets on enemies.
 Energy Tanks
These will be critical to your success. Each energy tank raises your permanent shielding by 100 points, allowing you to survive longer. Gather as many of these as possible.
 Energy Transport Module
Not really a weapon, but is required and obtained very early, allowing you to complete your quest. Acquired by defeating the Dark Alpha Splinter.
 Light Beam
Amazingly, acquired very soon after the Dark beam. It roughly has the same rate of fire and speed as the Plasma Beam and roughly has the same "ignite" properties. It shoots bursts of light energy, incredibly useful against dark creatures such as the Ing and creatures possessed by the ing. A charge shot will shoot a powerful burst of light. Like the Dark Beam, it also has additional properties such as causing objects to grow, expand, opening light portals and energizing light crystals. The charge beam combo is the sunburst contrary to the name it isn't all sunshine and flowers it will ignite any and all enemies plus near by objects on fire it costs 30 units of light beam ammo plus 5 missiles. Again like the others its fairly slow moving so use it on an enemy that's going to be in one place for a while.
 Light Suit
It's a shame that you get this suit so late in the game. It makes Samus look pretty slick, as well as completely negating the effects of Dark Aether's environments. It also allows you to enter extremely volatile areas that you previously couldn't with the Dark Suit, such as into an Ing Storm or into Dark Aether's water contrary to this you still are damaged by phazon so don't think your invincible. It also lets you travel though the light transport system from temple to temple.
 Missle Launcher
The first upgrade you collect is the Missile Launcher, an invaluable source of homing explosives. In one form or another, it's one of your most-used weapons. What? You say you start out with the Missile Launcher? Welcome to Metroid Prime. This allows you to shoot concussive blasts. No more rapid fire missile exploit, though. Find as many of these as possible to use with Missile combinations. This weapon opens Red Hatches. If you lock onto a target, the missile will home in on it.
 Morph Ball Bombs
Morph Ball Bombs
I'm sure you've had enough of being a sitting (er, rolling) duck while in the Morph Ball, right? Right. It's time to get some bombs again. The unlimited use energy explosives will serve you well over your adventure on Aether.
 Power Beam
Your default beam with the highest rate of fire and infinite ammunition. Though it is the weakest beam, you'll surprisingly be relying on this weapon more than ever. That's because it's the only weapon that has infinite ammunition and fires incredibly fast. You never lose this weapon. The Power Beam can be used to light beacon points along with the Light Beam.
 Power Bombs
A rare and powerful item that allows you to release a high grade explosive. This is the only weapon that can destroy DENZIUM materials found on Aether. This weapon opens Yellow Hatches. Acquired by defeating the Power Bomb Guardian. Unlike their cousins the morph ball bomb these do not come in unlimited numbers so use them sparingly.
 Scan Visor
Allow you to gather information. Aside from the graphical overhaul, the scan visor's function is unchanged. There are different colors while in the scan visor red is vital and must be scanned. Red objects are usually switches and hologram doors. Blue is interesting, blue things are usually enemies and random things like soldiers and lore. Green is something you have already scanned.
 Varia Suit
Your default suit. But since there are no "heated" environments in Echoes, this is a moot point. You never lose this suit.
 Grapple Beam
You can grapple to special targets, to grapple to multiple targets wait until the second one turns blue then briefly let go of the y button and quickly press it again. Acquired by defeating the Grapple Guardian.
 Gravity Boost
The equivalent of gaining the Gravity Suit, except you now have a third jump underwater. After doing a second jump, you can hold the B button a third time to slowly drift higher into the water.
 Screw Attack
The old screw attack from the previous Metroid games. This weapon is tremendously useful, giving you the ability to do a true space jump (you can only jump continuously in the air 5 times, to my knowledge). You are also engulfed in destructive energy, destroying roughly anything that comes into your path. Be careful though, if you hit something that can't be destroyed, you'll bounce back (and possibly off a cliff if you're not careful). You can also use this to wall jump to special surfaces.
 Seeker Missles
Allows you to shoot multiple missiles. Performed by charging your missiles. If you lock onto a target, you will see orange dots that correspond to how many missiles will be shot at the target. You can shoot at five separate things or unleash the entire five on an unlucky enemy. It is also used to open purple doors.
 Space Jump
Allows you to double jump. Acquired by defeating the Jump Guardian.