Metroid Prime featured some excellent gameplay mechanics at E3. It's quite impressive how the game looks like a first person shooter, but doesn't quite play like one. You always have plenty of options and below, you can get an idea of what they are and how to use them.

The Controls

Option Explanation
Target Lock: Allows you to lock onto an enemy and move around. Stay on for as long as you hold the button down.
Grapple Beam: When a grapple point becomes active (it's blue and looks like a grapple hook), you just tap L and your grapple beam will connect with the point and you'll fly across the gap. The grapple points can be used as single grapples or in a succession of them.
Scan Item: When you have the scan visor selected, you can scan items. Hold down the L button and a little bar will appear near the centre of the screen. Once the bar is filled, something will be activated or you'll get some information.
Change Visor: By pressing the D-Pad up, down, left or right, you can select a visor to use. Up selected the combat visor and left selected the scan visor. Default is combat.
Change Weapon: By pointing the C-Stick up, down, left or right, you can select a weapon to use. Up selected the power beam and right selected the right the ice beam. Default is power beam.
Jump: Hit B and you'll go right up in the air at any time.
Sidestep: This is an interesting one. When you're locked on, you automatically sidestep. The demo said that you could dash by pressing B and a side direction, but I never could get it to work because when you hit B... you jump. They could've meant that you do a fast, low-flying jump, but it was hard to tell. Should be cleared up when the game's released though. Interestingly enough, I found that if you held down the L button just a bit with an enemy around, you wouldn't lock on, but you could strafe.
Fire beams: Pretty simple. Fire a single shot, or press it a lot and fire a bunch of shots.
Hold to charge: Hold the A button down and your gun will charge up. When you release it, it'll create a powerful blast that can be used to shoot through rubble in your path.
Morph ball bomb: You can lay a morph ball bomb that goes off in a couple seconds.
Morph ball: By hitting X, you can change into and out of the morph ball mode. The morph ball allows you to go into small spaces and to move quickly.
Shoot Missiles: You can select the missile launcher by hitting Y and fire by hitting Y again.

The Weapons

The Beams:

The power beam is your standard weapon. It lets Samus open doors and can take out enemies. Other than that though, there's not much to it. The ice beam on the other hand actually paralyzes an enemy. Of course, it doesn't hurt the enemy as much, but gets the job done. Both of them can be charged up to fire a powerful blast.

The Missile:

When you hit the Y button, the end of your gun opens up, indicating that you can fire a missile. Hit Y again and you'll send a missile flying with a blue lightning-bolt like streak behind it. It's good that it works like this, because you only get 15 to start off with, and I'd hate to waste a missile by hitting the wrong button accidently. Of course, if you want to get one off in a hurry, tapping Y twice works just perfectly.

The Morph Ball Bomb:

While in the morph ball mode, you can lay a morph ball bomb. This bomb looks light blue and goes off in a couple seconds after you dropped it by hitting A. You can use them to open doors and blast through weak barriers. You can only set 3 at a time and then you have to wait. The number you've laid is located in the top right hand corner of the screen. It's represented by three highlighted blue symbols and as you lay each one, they become unhighlighted. After a few seconds, they become highlighted again, ready for use.

Misc:

  • One of the most highly looked over weapon features in Metroid Prime at E3 was the "super shot" (most likely because it was never listed anywhere on the floor). You can hold down A to charge for a powerful blast, but when you're power beam is fully charged, you can actually hit the Y button to perform a super shot. The super shot eats up 5 missiles, but is incredibly powerful if it connects. The best demonstration of this came with the ice beam. If you performed a super shot with it and you hit a wall, ice would cover most of the area that you shot.

  • Another weapon said to be available in the game is a flamethrower. It's possible that this "flamethrower" may just be a fire beam that can set things on fire, but we'll just have to wait and see. After that, they've got room for one more weapon in the other slot.

The Visors

Combat:

The combat visor is your default visor. It has basically all of your essential options on it. While in this mode, you can fire your beams and missiles. The area bordering your visor gives you important details, which are listed below. You can use this image for reference.

Position Explanation
Top Left: Radar.
Top Centre: Health bar. Underneath it, you can get an enemy health bar if you scan the enemy.
Top Right: 3D Map.
Bottom Right: Weapon select.
Side Left: Environment Hazard level. The environmental hazard level is labelled with an exclamation point. Let's just say you walk near a fire. The level will rise as you get closer and you'll eventually start taking damage. Walk away and everything's just peachy.
Side Right: Number of missiles remaining.

While you're in the morph ball mode, things become quite limited. All you can see is the health bar at the top left of your screen and the amount of morph ball bombs you can activate in the upper right portion.

Scan:

Not much to be said here. When you've got the scan visor activated, all you can see is your health bar. Then if you scan something, a little bar will appear near the centre and show you how long it's going to take to complete scanning.

Misc:

  • Only two scanners were shown during the demo, but the other two appeared in footage of the rest of the game. They include the infrared visor and the x-ray visor. Aside from the obvious titles of the visors, not much else is known about them.