Clank Levels were levels in which the player controls Clank on his own. Such levels occurred in most of the Ratchet & Clank games, but usually only two or three times per game, excluding Ratchet & Clank Future: A Crack in Time. Gameplay revolved around Clank issuing commands to Gadgebots, Microbots, Zoni, or his "past selves" (depending on the game).
Commands that could be given to Gadgebots (which appeared in the games set in the Solana Galaxy) were Follow, Attack, Wait, and Enter. Standard Microbots (from Going Commando) had the same commands and the additional Salute command, but special Microbots may have also have been commanded to Lift, Build or Retract a bridge, or Hammer. In Tools of Destruction, the Zoni commands were Follow, Manipulate, Charge Up, and Levitate.
Ratchet & Clank
The very first Clank level in the series was on the Blarg Tactical Research Station, where Clank explored the outdoor part of the station because Ratchet could not breathe in space. He then retrieved a Hydrodisplacer and brought it back to Ratchet.
The Kogor Refinery on Orxon was a Clank level, because the atmosphere was too polluted for Ratchet to breathe. Clank explored the abandoned factories and found the Magneboots and an Infobot for Pokitaru.
Ratchet & Clank: Going Commando
The first Clank level was in Megapolis, where he had to free Ratchet by unlocking a door.
Ratchet & Clank: Up Your Arsenal
The first Clank level was in the Deep sea base on Planet Aquatos, where Clank was entering the base through a ventilation shaft. He was aided by Skrunch, who would follow bananas fired from the BGAMD.
The next level came when Clank was filming an episode of Secret Agent Clank. Skrunch aided him again, in the role of Clank's chauffeur.
The third level was near the end of the game, at Qwark's hideout. Clank went down into an icy area where he fought his way through Lawn Ninjas and security where he found a switch that opened the forcefield to Qwark's hideout.
Ratchet & Clank: Size Matters
The second level occurred when Ratchet was kidnapped; Clank was dumped in Junkyard LXIV on the planet Metalis and had to fight in the Robot War III destruction derby in order to get off the planet and rescue Ratchet.
The third level occurred on Dayni Moon, where there was a second round of Robot War
The Technomite Ruins level was the first in the Ratchet & Clank series where you could return to a Clank Level.
Secret Agent Clank
Most levels in this game featured Clank on his own.
Ratchet & Clank Future: Tools of Destruction
Ratchet & Clank Future: A Crack in Time
In this game, after feeling that Clank was becoming dependent on these other robots, Insomniac Games decided to base the Clank levels on Clank doing things on his own. Clank gained the ability to copy himself through time and perform tasks in this manner. The Chronoscepter was a weapon Clank used which had the ability to throw time bombs; creating bubbles that slowed down anything inside. Also due to his separation from Ratchet, these levels were much more prominent in this installment than in others.