Bonus level:
     Successfully complete story mode to unlock a bonus "infinite" level.

Blast Helm:
     Defeat the Infinity level 50 Boss.

Inferno:
     Defeat Colossus (Sector 2 Base Boss).

Judgment:
     Defeat Enforcer (Sector 2 City Boss).

Neutron Gun:
     Defeat the Infinity level 30 Boss.

Onslaught:
     Defeat the Infinity level 10 Boss.

Surge Helm:
     Defeat the Infinity level 40 Boss.

Trident:
     Defeat the Infinity level 60 Boss.

Vulcan:
     Defeat the Infinity level 20 Boss.