Metroid Prime 2: Echoes/Boost Ball

Torvus Bog
You've now explored a good chunk of Torvus Bog; now it's time to explore the Dark side of it.

Torvus Temple
Return to Torvus Temple and get to the lower part of the room if that's not how you got in. If you're in the upper part, then scan the Emerald hologram to activate the lift if you haven't already.

Scan the door with the Emerald hologram to open it and go through the door behind it. This is the door on the right if you're coming from Temple Access.

Underground Tunnel
There is a Grenchler here and it can be an awkward fight since it's tricky to get around behind it in close quarters. Before moving on, switch to Morph Ball and roll under the ledge at the entrance for a Missile Expansion.

Continue to a part of the passage with a low ceiling and switch to Morph Ball to get through. When you come out there are Sporbs waiting, so quickly switch out of Morph Ball and use Missiles on them. Get the history scan here and use the White door.

Torvus Grove
Cross this room and just before you reach the opposite door a new type of Pirate attacks. They are Pirate Commandos, the Light version of the Dark Pirate Commandos you may have met before. When you defeat them, the opposite door is unlocked so you can get through.

Meditation Vista
Use the portal here. There is a platform moving around in the distance, but it's another teaser since you can't reach it until late in the game.

Gloom Vista
There's nothing here but the portal so go through the door.

Polluted Mire
Hunter Ings, a new type of Ing, are waiting for you here. Shoot them with the Light Beam, but only when you can get a target lock since otherwise the shot will just go through them. Follow the trail of platforms and ledges that circle the central "tree" to reach the Black door.

Dark Falls
There is a save station here and it's a good idea to use it because a boss battle is coming. Be sure to hop over the poison water as you come out of it. Continue up the ramp.

Dark Forgotten Bridge
This is a passage on one side of a room you've been to before, but you can't get to the main part of the room, at least for now. Defeat the Lightflyers to create safe zones here.

Dark Arena Tunnel
Switch to Morph Ball and start across the long series of disappearing blocks. There is no way you can get all the way across without falling through, but you can jump out at the other side. You won't be able to get back once you do though, which is a sign that you'll be getting a new ability soon.

Dark Torvus Arena
As you step into the room you get a short view of a large Ing which turns into a Morph Ball and escapes through a tunnel on the far side. Drop down from the ledge and recover your energy in the safe zone, then follow the Ing into the tunnel. You meet the Ing again and a battle begins.

Grab the refills the monster drops, then get the Boost Ball upgrade it leaves behind. There's still no safe zone here so get back to the one in the main part of the room and recover.

The first thing to do with the Boost Ball to get the key from the wall. The room here has a U-shape which the game calls a half-pipe. If you've played Metroid Prime then using the half-pipe will be familiar, if not it's still pretty easy and you can practice while you're recovering in the safe zone. Roll to one side of the U, then start a boost and roll back, releasing the energy just as you pass the lowest point. If you did it right you should go a bit higher this time. Start another boost and release it at the lowest point going the other way to go even higher. It's best to just let gravity and the boosts do the work, so don't use the control stick. Also, start the next boost as soon as you can after a release; that way you should be up to full power on the next swing. Keep pumping this way and you can get quite a swing going. Note that the camera positions itself to give you a good vantage point for this.

If you start in the middle the half-pipe swing should take you to the key. Once you've gotten it, do the maneuver again starting closer to the exit so you can reach the ledge and the exit.

Dark Arena Tunnel (cont.)
Now that you have the Boost Ball you can zip over the disappearing blocks before they go away, allowing you to get back. Continue on to Dark Falls where you might want to save your progress.

Torvus Grove
The next upgrade is in the Temple Grounds, not Torvus. But there are some expansions to collect as long as you're still here.

Get back to the portal and return to the Light side, then continue back to Torvus Grove. Look for the half-pipe near the entrance to Underground Tunnel and use it to reach the ledge above. Follow the ledge around to the right and go through the Black door.

Grove Access
Get a scan of the small creatures here, then continue to the next room.

Forgotten Bridge
This is a side passage as in Dark Forgotten Bridge, the difference is that you can use the Spinner here to open the doors and connect the two parts of the room. This opens the doors in the Dark side as well.

Plaza Access
Switch to Morph Ball and start to explore the maze here. The idea to the reach a bomb slot to change the configuration, which then allows you to reach the next bomb slot. This changes the configuration again so you can reach a tunnel in the middle. Go through to find a half-pipe withing a Morph Ball maze. Boost up to the ledge on the right to get a Missile Expansion, then go back.

From here you can continue on to another room, but this turns out to be a dead end for now, so go back to the Forgotten Bridge.