I know that platformers are not the most popular thing around here (except for Tomb Raider which has just been getting worse and worse as the series progresses), but this one is definitely worth playing.
First, this is a game for the Playstation 2. It is also now available as a Greatest Hits selection meaning it is available at a reasonable cost. It's not available for any other system.
This is a fast (but not too fast) and sometimes difficult (but not too difficult; after all, I finished it) and fun game involving Ratchet, a dog-like alien, and Clank, a tiny and amazingly-not-annoying robot. As Ratchet you set out to help Clank stop a interplanetary conspiracy forged by the evil Chairman Drek who wants to make a replacement world for his race by taking pieces from other worlds. You start by helping Clank to find the superhero Captain Qwark but eventually you end up being the one to save the day (I'll leave the storyline out of it, no plot spoilers). As you go from planet to planet, you pick up a variety of weapons and gadgets which help you progress through the game.
The weapons are some standard fare, such as blasters and bombs but there are a few neat ones. A morph ray which turns your enemies into chickens is kinda fun, as is the "glove of doom" which tosses out little robots which seek out and destroy nearby enemies. Each of these have only a certain amount of ammo which can be replenished by finding random ammo or by purchasing it.
The gadgets are things like the trespasser (which helps open locked doors after you solve a small light puzzle), the hologuise (which makes you look like a robot so that you can sneak past difficult guard-bots) and magnaboots (which let you walk along metal surfaces, even upside-down).
Weapons and gadgets are either bought (using bolts which are the common currency of the game) or earned (by reaching a certain point in the game or getting something for someone, occasionally from a different planet).
The gamuts you must run on each planet are, each in their own way, a challenge which is accomplished by using a few common elements and sometimes specific weapons and gadgets. They, of course, get progressively more difficult, leading to the eventual "final boss battle". Running and jumping are the standard with special jumps that you learn being the additional help for some of those hard-to-reach spots. As well, there are hidden gold bolts (which help you buy advanced "golden" versions of some weapons when you replay the game) as well as skill points for accomplishing certain mystery tasks. The voice acting is excellent and the cut-scene cinematics are fun.
Overall, one of the best platformers that I have played. Scorewise, I give it a 9 out of 10. As well, I eagerly await Ratchet & Clank 2 - Going Commando which is supposed to be out either late this year or early next year.