How to get multiplayer Extras
From M2K2: Metroid Prime 2 Wiki
By SamusAranLuver Discovered By Tim Casey
Things in the game triger multiplayer extra and you might not even notice it.
Extras____________________Requirements
SoundTracks
Luminoth__________________Talk to U-Mos For the First time
PirateFear________________Restore Energy to Agon Temple and talk to U-Mos
Torvus Bog________________Restore Energy to Torvus Temple and talk to U-Mos
Santuary__________________Restore Energy to Santuary Temple and talk to U-Mos
Darkness__________________Finish the game
DarkEchoes________________Finish the game
Arenas
Pipeline__________________Restore Energy to Torvus Temple and talk to U-Mos
Spires____________________Restore Energy to Santuary Temple and talk to U-Mos