Firstly, before you read my post, cube.ign.com explain these parts of the game in detail, it will really help you with what you are looking for.
Just to summarise, Metroid isn't an FPS, it's an FPA, hence it the gameplay mechanics aren't mainly based around shooting. If you played the first metroid, I am sure you would know thaat aiming you shots wasn't really that hard. So in other words, this will make the transition from the 2d, to 3d easier.
If you want to know more about the controlls, and strafing, then head on over to cube.ign.com
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