Save the overrun planet is a mission in Going Commando taking place in Allgon City, Damosel. After seeing a Darla Gratch news report on the Protopet crisis on Damosel, Ratchet and Clank decided to travel to the planet themselves to save it. At the end, they met the Hypnotist, who offered to make them a Hypnomatic if they had enough parts.
No new weapons are available at the Megacorp vendor. The enemies you will encounter are the Protopets, which are small melee enemies that multiply rapidly if not all are dealt with (and if even one is left alive they can quickly multiply into several more), and Extermibots, durable enemies which come in squads and fire blasts of lightning or ranged bombs from their pistol, or kick you when in melee range. Due to the sheer numbers of the Protopets you face, the Plasma Coil, Bouncer, Hoverbomb Gun, and Shield Charger are by far your best bets, and will also be useful against the Extermibots. The Sheepinator is also effective against the Protopets, as it does not use ammo. As usual, the Synthenoids and Miniturret Glove are excellent for dealing with the Protopets when overwhelmed, and specifically worth using when upgraded. Protopets appear from trash cans, sewer holes, and other areas, so ensure that you eliminate all of them and watch your back in case you missed one and they managed to recover behind you.
The mission is begun by heading straight forward from where the ship lands onto a street. The street will immediately be filled with Protopets, while two Extermibots will arrive at the end of the street from a dropship. Take them out, then use the ladder at the end to climb to the top of a wall. Kill the Extermibots here, and then use the Swingshot across a gap. You will reach an area in front of a park, with several Protopets coming from the trash cans before the gate to the park opens. To proceed, you have to kill all the Protopets and Extermibots and destroy the trash cans they spawn from before you can go inside (an easy way to do this is to use the Hoverbomb Gun to destroy the trash cans in one hit, and then the Plasma Coil or Bouncer to wipe out the remaining Protopets).
When inside the park, you once again need to destroy all the enemies before the exit to the park opens. When the exit opens, head outside and jump across the gap onto the street, then follow the path until it is blocked by a red bus crashed in front of a store entrance; kill the two Extermibots on top and then proceed through and use the taxi.
The taxi takes you to the downtown bank, at a balcony below the entrance, with a vendor. Restock on ammo, then wall jump up to the top to enter the bank. Clear out the enemies, then head up the stairs, take out the Extermibots, then head through the exit outside. You will encounter some Receiver Bots here, which can practically be ignored. Use the Heli-Pack to get up the ledge at the end then follow the path right to an area in front of a grocery store. First, destroy the trash cans and then kill the Protopets and the Extermibots on the ground. To progress, you have to kill two Extermibots on the roof of the store first, which can only be done with ranged weapons like the Pulse Rifle or Minirocket Tube. After killing them, the entrance opens.
Head inside and kill the Extermibots then head through the exit at the back and take the elevator up to another park. Kill all the enemies in here, then use the Thermanator to freeze the water at the back so you can head out through the exit. Go through the exit to commence a short cutscene, leading to the next mission, "Bring Hypnomatic parts to Hypnotist". If you do not have the parts to complete this mission yet, use the taxi to return to your ship.