Was at one point titled Ratchet & Clank: Four Play which can be seen on some concept art.
When Dr. Nefarious reanimates the Z'Grute from cyrosleep, he cries out "It's Alive! It's Alive!" while laughing maniacally, similarly to Dr. Frankenstein (Colin Clive) cries out the infamous line in the 1930 horror classic "Frankenstien".
T.J. Fixman thought it would be funny that Captain Qwark be Galactic President.
This isn't the first Ratchet and Clank game to feature cooperative multiplayer. Deadlocked is the first.
Greg Baldwin built models and the developers added a new polygon count and a new game scale.