What happens to a pair of over-achieving heroes after they've vanquished evil, saved the universe and just been all around nice guys? If we're to believe the opening cinematic of Ratchet & Clank: Locked and Loaded, they get bored. Really, really bored.

Stuck at home with nothing to do but watch TV and reminisce about the "good old days," Ratchet and Clank start out their new adventure as the spitting image of desperation, which makes them the perfect pair to aid Mr. Abercombie Fitzwidget. It seems that the slightly wacky businessman has lost "a valuable biological experiment" and he needs help getting it back. That's where our dynamic duo come in. They're heroes without jobs and he's a man in need offering to pay. Without a second thought, Ratchet and Clank are off on the start of a new adventure.

Originally subtitled Going Commando (and remaining so in North America), the name of the game has fortunately nothing to do with underwear, and everything to do with the game's style of play. If the original was all about big guns and large explosions, Locked and Loaded is all about bigger guns and larger explosions. Rambo's got nothing on these two.

You'll start out the game with a piddly two weapons, but that number soon expands up to 20 as the game progresses. The majority of those weapons are upgradeable, essentially doubling the amount of firepower available in the game. There is plenty of variety in the weapon selection, with everything from a lava gun to a sheep blaster (don't ask) appearing. Five weapons from the original game also make a re-appearance - if you have a Ratchet & Clank save on your memory card, you can get them for free, but if not, you'll have to buy them in-game.

Level design has a heavy focus on both platform elements and fast action combat, so expect to be doing a lot of jumping as well as plenty of shooting. While the jumps do not require the precision of a brain surgeon, they do present a fair challenge in the latter half of the game.

Puzzles usually take the form of simple actions, such as moving an item across the room, or flipping the right switch. You won't find anything too mentally taxing here - the game tends to challenge your fingers more than your gray matter.

Combat takes place in a third-person viewpoint, with the emphasis on mass destruction. Control of the main characters feels very natural, and much tighter than the original game. Weapons will earn experience alongside the player, so it is to your advantage to use your weapons as much as possible if you want to make them more powerful. Remember: a bigger gun is almost always a better gun.

Enemies will gain experience and health in a level that is proportionate to the player, so don't expect things to get easier as you move through the game. Initially, your opponents will go down in one hit, but by the time you get to the end of the game, most will take multiple swings before they go down for the count. Compared to the first, the challenge has definitely been upped a notch.

New to this iteration of the game are the sphere worlds. Exactly what the name implies, the sphere worlds are just that - levels that are built entirely on the outside of a sphere. Different than your typical platform game levels, the sphere worlds help keep things interesting.

In addition to the mayhem and destruction that is the central focus of the game, Insomniac has also included a number of mini-games that allow players to take a breather. Some of the mini-games are simplistic, like the sideways Space Invaders clone, while others are a bit more involved, such as the hoverbike racing contest. All of them are well integrated into play and feel as if they belong, rather than simply being added as filler.

The developers have upped the ante in the graphics department with Locked and Loaded by a considerable degree. Compared to Ratchet & Clank, the new game looks leagues better. In addition to the greater amount of detail, Ratchet also sports a new, more weathered look as opposed to the boyish flair he had in the first. Progressive scan and 16:9 support also ensure than anyone with a high definition TV will be a happy camper.

Rounding out the package are a number of hidden secrets that add to the replay value of the game. Some of them are visual -- such as the different suits that you can unlock for Ratchet to wear -- while others change the way the whole game plays. Perhaps the coolest is the first-person mode toggle that unlocks once you beat the game for the first time.

Exceeding the quality of an original is always difficult, but that feat has been nailed with this sequel. The story may not be deep, but Rachet & Clank: Locked and Loaded has it where it counts - fast action and plenty of it. Highly polished and loads of fun, if you want an example of platforming paradise, Insomniac has delivered.