If you like linear games forget metroid , they are all about exploration and item fetching to open up new unexplored areas and both prime 1 & 2 are absolutely huge so don't even think about finishing the game quickly.. In short metroid is not for light play, it takes a lot of time and effort.......
however if your up for a challange MP3 might just turn out be one of the best game experiances you ever had...Metroid prime was infact my favourite gamecube game..yes even more than the mighty resident evil 4...
as for your initial question there are other reasons besides MP3 why you should own a wii.. zelda Tp is fantastic and games like wii sports and warioware might surprise you if your into light play...as for me the main reason has a name...its called super mario galaxy...;)
