Fight some robots

Fight some robots is the first mission of Size Matters. Ratchet and Clank were relaxing on a beach on Pokitaru when suddenly, a little girl by the name of Luna approached them and asked them to pull off some heroic moves for her school report on heroes. While the two were reluctant at first, they decided to show her what they're made of.

Luna led the two around the resort, where they fought several old training robots and scuttle crabs. Once they returned to their initial location, Luna was amazed by Ratchet's performance, and was excited to show everyone the pictures. Captain Qwark then appeared, trying to conceal himself in the paper he was reading until Clank recognized him. As Clank tried to get Qwark to explain why he was there, Ratchet approached them and complimented Qwark on his hat, which led to Qwark bawling as he revealed what happened to his long-lost parents. Clank then suggested to Qwark that he should try to find his real parents, and shortly after, enemy robots confronted them and captured Luna, stowing her away aboard their ship. Ratchet and Clank set off to rescue her.

Walkthrough
You'll start off along the beach. Here, you'll find some breakables such as chairs and crates. Luna will lead you through the area. Follow her and listen to the instructions she gives you. Head up the small path left of the vendor, where you'll encounter some blue scuttle crabs; give them a whack with the OmniWrench, and then approach the high wall. You'll be prompted to perform a boost jump ( + ) in order to get over the wall. Once on the other side, you'll encounter some old training robots. Use any attacks necessary to survive their attacks. This would actually be the perfect opportunity to use your Lacerator.

Now that the robots are down, you must activate the bolt crank to open up the door. After passing through the door, you must now perform a stretch jump ( + + ) to cross the gap ahead. Next, you'll be prompted to shoot the target on the gate by entering first-person mode with your Lacerator. Once through, you'll come across a large waterfall, encountering more crabs. After taking them out, do another high jump to reach the ledge above, where you'll find more robots. Luna will prompt you to use your Acid Bomb Glove (though it's optional), which is great at taking out multiple enemies. Afterwards, slide down the sandy slope to an area with beach house that robots will appear from.

Continue following Luna as you fight more crabs and robots along the beach. You'll be crossing the water to reach a small holm, taking precautions not to fall into the water, or you'll be swallowed alive by a shark. At the holm is another bolt crank you must turn to activate the bridge. Along the bridge is your first piece of armor you'll find in the game. Continue across the bridge to trigger the a cutscene leading to the next mission.