The game takes place between Super Metroid and Metroid Fusion. After escaping the exploding Planet Zebes, Samus wakes up on a Galactic Federation ship. After leaving, she receives a distress call from a dormant "Bottle Ship", which is floating a short distance away from a Federation vessel. Upon stepping into the ship, Samus encounters a group of GF soldiers, led by Anthony Higgs, who fought alongside her before she left the GF military.
The game is played holding the Wii Remote horizontally, like the NES controller. Normally, the game is played in a third person perspective, where Samus can jump, shoot her arm cannon and turn into a morph ball, similar to the classic Metroid titles (however, movement is not strictly limited to a 2D plane). By pointing the Wii Remote towards the screen, the game changes to a first person view, where Samus can lock onto targets and fire missiles.
There are several instances where players will have to constantly switch between play modes; for example, playing in third person to fight off a horde of flying enemies, whilst switching to first person to destroy their spawn points. Additionally, the first-person perspective is also used in exploration, as when locating hidden items such as missile expansions and energy tanks.
Metroid: Other M isn't just a side scroller. It's a first-person shooter. And a third-person exploration game. And seemingly everything in between. And thats what makes it such a highly anticipated Wii game. Check out the games trailer.