Metroid Prime 2: Echoes is purely and happily a video game. This sets it apart from many of its contemporaries, which are OK with being video games but which, now that we're asking, would really much rather be Jerry Bruckheimer movies.

A case in point is Halo 2, the game to which Echoes is most often compared. That mega-selling Xbox shooter is terrific as an exercise in play, true, but if that were the end of its ambition we would not be hearing persistent reports that Ridley Scott will direct a Hollywood adaptation beginning sometime in 2006. Halo is a sci-fi story with deep roots in Star Trek and the books of Larry Niven. Halo is full of cinematic cut-scenes. Halo contains many actual performances by actual paid actors.

Halo also wades frequently into the rennet and is at best an aspiring B-movie, but there is no denying that it holds storytelling, with all the attendant narrative arcs and beginnings and middles and ends, near and dear to its heart.

The new Metroid is not at all interested in story. Oh, it makes a perfunctory effort in the manual with some dullish text about a grand battle between the Forces Of Light and the Forces Of Dark, but in general it couldn't care less about what happens next. Instead it focuses on what happens now. It strives for a sense of place, not plot. It is a plaything. It understands that the very idea of a Metroid movie is absurd. It celebrates that. It is a game. It is also one of the very best games of the year.

We play as Samus Aran, a space bounty hunter in a ridiculous suit of shiny bronze electric space armour. Samus is a woman, and through the green glass shield of her helmet we can see that she wears eyeliner, but in most other respects she is very much like Master Chief, the hero of Halo, who also wears a ridiculous suit of shiny electric space armour. So Samus does not speak much, and she takes zero crap from anybody, and also she handles a raygun as if it were a part of her. This is convenient, for indeed it is a part of her. The entire right arm of Samus's armour suit is a giant space cannon, a multi-purpose barrel of death with an everlasting supply of buzzing space energy shots.

As the game begin, Samus has crashed her spaceship on a planet called "Aether." Unfortunately, Aether is stuck in a dimensional warp thingy, and is drifting in and out of phase with a parallel universe. This is indicated by glowing clouds of dark purple and black. The parallel universe contains another planet Aether, which is just like the original, except that it is "Dark." As the game plays out, we (as Samus) travel many times from regular Aether to Dark Aether and back. We play through the same spaces in the bright sunshine and the purple fog, hoping that a change we make on one side might help us solve a puzzle on the other.

We look closely at everything we see using the "scan" visor on the suit of armour. Sometimes this provides useful information. Sometimes it unlocks doors. Sometimes it unleashes a horde of trans-dimensional nasties. Sometimes it tells us where on their underbellies our shots will be the most effective. The game is full of shooting, so much so that it does not even contain latches or handles. Want a door open? Blast it with your cannon.

Echoes plays from the same first-person perspective Halo does. It is only available for the GameCube, and Halo 2 only for the Xbox. Its heroine wears the same clothes and breathes the same air as the guy from Halo. It is no wonder that discussion boards across the internet are buzzing with idiotic fanboy debates about which game is better and whether Samus Aran could kick Master Chief's ass. But the two titles are fundamentally different from each other, in a way that is not immediately obvious. Echoes is quieter and lonelier. Samus is all on her own. There are no space marines to crack jokes or trade guns with. Nobody else draws enemy fire.

Echoes is also more deliberately paced. Many of its rooms and fields are free of both friends and enemies. In these, the challenge is not just to blast our way to the other door, but to figure out where the other door is. Or to find a route, across catwalks and ledges and impossible-looking cliffs, that will get us to the translator module that will allow us to unlock the door once we do find it. It is a series of logical puzzles interspersed with a series of jumping puzzles, slathered with fierce blasty bits of shooting.

It is quick and exciting, and the battles will quicken your pulse. But its real beauty is in its quiet moments, when you put down the cannon and look around, scanning every little thing in every little alcove, wondering where to go next. It is like being lost in a strange land with a map you can't read. Even when it is silent, it is exhilarating.