Collect the indicated number of parts and combine them to unlock the corresponding weapon:

Heat Seeking Warheads: Collect 700 Parts
Hyper Plasma Ball 1: Collect 300 Parts
Hyper Plasma Ball 2: Collect 400 Parts
Plasma Artillery 1: Collect 200 Parts
Plasma Artillery 2: Collect 300 Parts
Plasma Ball 1: Collect 100 Parts
Plasma Ball 2: Collect 200 Parts
Rocket Launcher 1: Collect 500 Parts
Rocket Launcher 2: Collect 700 Parts
Shock Wave 1: Collect 400 Parts
Shock Wave 2: Collect 500 Parts
Spread Shot 2: Collect 100 Parts