In Lost Planet 2 for Xbox 360 and PS3, there are several weapons you can unlock, primarily by leveling up with certain factions. Here is the list of weapons you can unlock, and what you need to do to unlock them:
Akrid Launcher – Reach Level 50 with the Snow Pirate Elites faction
Energy Gun SP – Reach level 70 with the Femmes Fatales faction
Firecracker – Reach level 30 with the Femmes Fatales faction
Gun Sword SP – Reach level 70 with the Rounders faction
Hand Cannon SP – Reach levl 70 with the Rounders faction
Machine Gun SP – Only weapon unlocked without the use of factions, simply have a saved game from the Lost Planet 2 demo
Plasma Cannon SP – Reach level 50 with the NEVEC faction
Plasma Gun SP – Reach level 30 with the NEVEC faction
Shotgun SP – Reach level 50 with the the Femmes Fatales faction
Shuriken – Reach levl 30 with the Rounders faction
V-Device SP – Reach level 70 with NEVEC faction