You are right: More does not mean better, but the developers have created a longer, more enthralling story and extensive level, where is all the space.
Ratchet and Clank are from everyday life of a hero who has nothing to do, bored and take therefore inconsiderate a job to which increasingly emerges as a major problem. As the heroes begin to scrutinize the affairs, they encounter more questions and all sorts of characters who help them either, or they want to stop. Entertainment is guaranteed!
Technically the game compared to its predecessor was somewhat improved. The graphics are refined and the worlds see more details from rich. The control is the same as in the first part, but you have it more functions and moves. There is also the gameplay some new things, such as fighting in arena battles or faster pace race.
Who liked the first part of the Ratchet and Clank series, which may or this game should increase without hesitation. But not only fans will find pleasure in this game.