Since this is the second offering of the Ratchet and Clank Future series on the Playstation 3, I'll be using it's predecessor Ratchet and Clank Future: Tools of Destruction as a comparison point for this game. Tools has showed us what they can do with the system.
Graphics: While the graphics are very nice and clear, they are no where near as clean or as detailed as it's predecessor Tools. The cut scenes are, as in all of the Ratchet and Clank games, crisp and full of tongue-in-cheek humor. Being they are pre-rendered video files, it's not to hard to have good graphic quality here.
Sound: The sound is spot on. All the weapons were carried over from Tools and sound just like they should. The background sound really shines in the final level as well as the cave level. Never once was I wondering where a sound was coming from.
Control & Gameplay: If this is your first Ratchet and Clank game, the controls are very easy to pick up in the initial stage. Anyone who has played a Ratchet and Clank game in the past should be able to pick up the controller and jump right into the game. The addition of two new abilities for Ratchet's wrench (the ability to pick up some items/characters in the jaws of the wrench, and the ability to detach the wrench head to manipulate platforms and over various transportation methods.) was a little difficult to get the initial hang of where to stand to target something or how to throw something held in the wrench. But after a short while it becomes second nature.
Replay Value: As per the norm with Ratchet and Clank games, there are secrets in just about every level, and you'll probably miss them in the first playthrough. Unlike previous Ratchet and Clank games, there is no option for returning to the start of the game while keeping all of your weapons, weapon levels, and health level, allowing you a better chance to explore the areas you have cleared more thoroughly. There isn't a way to go back and replay levels you have already completed either. If there is I have yet to find it. Of course you don't really find out about these things 'til the end of the game. So if you are one of those people who like to have everything maxed out and 100 percent of all the items you have to start a new game and use a guide, or hope you get lucky and find all the mods and such in a level on a second playthrough.
Overall: While the lack of a challenge mode or replay mode was a bit of a disappointment the biggest let down (at least for me) would have to be the length of the game (six stages). Granted, it is more or less supposed to be just a filler between Ratchet and Clank Future: Tools of Destruction and the new Ratchet and Clank Future 2: ???(How Ratchet got his Clank back??) that is due out at the end of 2009. There are three difficulty levels, though they are all fairly simple (at least I think so). I guess I just expected more in the way of levels but other then that the story continuation and surprise at the end of the game were well worth the time. If they would have added 4 more levels and a challenge mode. I'd say that it would have been well worth the cash, as it stands if you love Ratchet and Clank it's a good game just really really short. If you've never played a Ratchet and Clank Game this is a good place to start to get the idea of how the gameplay is and who some of the major characters are. But to follow the story to its fullest, you would want to go back and play the other Ratchet and Clank Games.