There are 6 achievements worth 1000 points
All Stages Cleared (Easy - 50 Pts): Acquired after clearing all stages in Easy mode.
All Stages Cleared (Normal - 100 Pts): Acquired after clearing all stages in Normal mode.
All Stages Cleared (Hard - 150 Pts): Acquired after clearing all stages in Hard mode.
All Stages Cleared (Hardest - 200 Pts): Acquired after clearing all stages in Hardest mode.
All Stages Cleared (Inferno - 300 Pts): Acquired after clearing all stages in Inferno mode.
All Weapons Acquired (200 Pts): Awarded after acquiring all the weapons in the game.
Beat every mission on a certain difficulty to unlock the corresponding weapon.
Genocide Gun: Beat all missions on Inferno.
PX50 Bound Shot: Beat all missions on Hardest.
Y20 Impulse: Beat all missions on Hard
ZE Launcher: Beat all missions on Normal.
Zero Laser Rifle: Beat all missions on Easy.