Ratchet and Clank 3 Up Your Arsenal Walkthrough
Nefarious BFG, Koros
This is the robot city and the key here is to break EVERYTHING. This gets you tons of money and a skill point. Work your way along the path, bash and jump-smashing and slaying enemies. Work your way along the first island, making sure you get into all the nooks and crannies to get extra boxes.
You get to a closed door - it opens up as you approach and you jump across the broken bridge area. Clear out this courtyard area. Go up the boxes to the right. You up in a picnic area. Go around the building to the left and jump up the ladder for a titanium bolt.
Work your way forward to the continue ponit. Finally! you have a return to ship spot, a weapons vendor, and a giant yellow ship to destroy. Take out it and a few enemies. Head up and right, going past a small computer terminal area and along to a big robot. You get up to another big robot on a pillar. Slay him and head right.
You're at a grey bridge, and another yellow ship comes to defend it. You end up in a main central room. You see Clank turning the main gun and blasting the sphere. The Captain says you're not done yet. Nefarious constructed a new, deadly model. It's on Planet Mylon. It's guarded by an entire robot army.
Ratchet and Clank 3 - Up Your Arsenal Walkthrough