When you head off, back in Megopolis, a cute girl robot brings flowers to Clank. Unfortunately, the ninja shows up and steals poor PJ-wearing Clank!!

You're caught in a spaceship battle before you can get to the resort. Your keys are:

X fire guns
circle secondary
square turbo
L1/R1 barrel roll
L2/R2 straighten ship

You start out with Wave 1, of 20 enemy ships. Fly amongst the asteroids and shoot them, gathering up "Raritanium" as you go. You use raritanium for upgrading your ship later on. There's a second wave of 20 enemies, and you're set. Note that you can do other challenges here if you want, to get raritanium and have fun!

Ratchet and Clank 2 Going Commando Walkthrough