Without doubt the best Ratchet and Clank entry to date in the series.
In the first Ratchet and Clank, we were treated to tons of different weapons. All of them were extremely awesome. However, a lot of them had a ridiculously high price tag. The most bolts I've ever gotten in the first game is 40,000, just enough to buy the Tesla Claw. In Going Commando, weapons upgrades were added, a very cool feature. GC also brought some even cooler weapons to the gameplay. The addition of armor vendors was a nice touch, along with the upgradeable Nanotech. However, the problem with prices continued into the second game. The coolest weapons in the game are so astronomically priced that one will almost certainly not get all of the weapons from the game.
I give you the answer to all of your price dilemmas, Up Your Arsenal. In UYA, the weapons are not cheap, but they are amazingly affordable. In this game, you can get up to 10,000 bolts from just one battle alone. That adds up fast to give you the super-cool weapons and the armor. Annihilation Nation is a great way to earn bolts and it never loses its fun value. That is easily the most fun planet in the game, because you can go back and fight over and over again. Even the Qwarktastic Challenge, worth 200,000 bolts on the first time through the game, is not impossible to win.
There are also new types of weapons upgrades that greatly increase the interest of the game. Each weapon starts off at V1, then goes to V2, V3, V4, and then it hits the fifth level up. At Level 5, the weapon's name changes and it upgrades again. This seems aggravating, but it is actually a very nice touch to the game. I have a select group of weapons that I use quite often, and all of these weapons levelled up very quickly. Also, after you beat the game the first time, if you play Challenge Mode, you can buy the V6, of "Mega" versions of the weapons that you've upgraded to Level 5. These weapons will then upgrade again to "Giga", and then they will reach their final destination, "Omega", the most powerful incarnations of your weapons.
Another great addition is the new weapons, with the return of some amazing ones. The Plasma Whip is a pretty good new addition and is very affordable, making for a nice starting weapon. The return of the Suck Cannon is very welcome indeed, as this is the most accessible and easiest incarnation to use in all three games. A must-have is the Flux Rifle, a powerful sniper rifle that can do wonders against bosses and very large enemies. The Disc Blade Gun is infinitely better than the Chopper from GC. The Qwack-o-Ray is unbelievably effective, and is one of my most used weapons. All of the returning weapons are very welcome, as they include the Miniturret Glove, the Shield Charger, the Lava Gun (upgrading to the Liquid Nitrogen Gun, an insanely cool (no pun intended) weapon), the Bouncer, and the Plasma Coil. But the crowning achievement for weapons in this game is the Rift Inducer. This weapon, when fired, creates a black hole that will suck up enemies that get too close to it. This is definitely the most unique and the coolest new weapon in UYA.
The storyline of the game is quite engrossing. It's pretty intense in some spots, but it never loses the fun of Ratchet and Clank. The main villain, Dr. Nefarious, is completely, totally, and ridiculously hilarious. He's easily one of the best things to happen to this game, along with his butler, Lawrence. There are cutscenes in the game involving Lawrence and Nefarious where I about died laughing. Such as Nefarious' audition for "Galactic Idol". The images are burned into my brain, but they're so funny.
All in all, Ratchet and Clank: Up Your Arsenal capitalizes on everything that made the first two games great, and makes it even better. The weapons are obviously the crowning achievement of the game, along with the affordable price tags on them. You'll play this game over and over and over. 10/10.