During the development of Project Gotham Racing 2, developer Bizarre Creations found they were bored with creating cars and designed a nifty little arcade shooter called Geometry Wars to pass the time. It was an instant hit amongst staff, and without hesitation, they hid it in Project Gotham Racing 2 as a bonus extra. While easy to play, the game was incredibly hard to master, and it wasn't unheard of to hear a gamer actually tune out of the racing for longer than they bargained for when they loaded this gem up. And with the advent of the Xbox 360 and the overhaul of the Live interface and Xbox Live Arcade, we have a brand new Geometry Wars in Retro Evolved (and the original is thrown in for good measure too).

The concept behind the game is maddeningly simple, but surprisingly engrossing. Using the left thumb stick to move your 2D ship around, you avoid and fire at your enemies with the right thumb stick. And that's all there is too it, really. You can fire in an alternate direction than where you are facing, and there is also a screen clearing bomb that is a life saver on more than one occasion, but the mechanics behind the simple appearance follow through to the easy to learn controls. It's the amount of enemies you'll face where the real challenge lies.

As you are boxed in a square that just reaches the outside confines of your television screen, numerous enemies will pour in from all sides, and your shooting is all that stands between you and being killed. The simple design of the enemies will swarm into the screen in packs, and shooting them with a variety of lasers (which change sporadically) will rack up high scores with multipliers and more achieving better scores and bigger thrills.

The two modes available are the original Geometry Wars, titled Retro, and Evolved, the brand new mode. Evolved is like Retro on crack, with far more colourful displays (reminded me of forgotten PS2 launch title Fantavision), exploding from your enemies. They act just as well as they did before, but Retro feels a little slow and lumbering in comparison to the new mode, and is one you won't find yourself spending a lot of time with.

The different multi-coloured enemies have different personalities, with the blue diamonds taking the suicidal route and coming directly at you no matter what firepower you're packing. The pink diamond will also aim at you, but will attempt to dodge fire. They also break into two extra particles which take a circular route around your ship in ever tightening circles. The snake like creatures have immune bodies but can be fired upon directly at the head, and the glowing circles don't move at all, but suck up all to it and must be disposed of quickly before they burst into many hundred little particles. There are others, but primarily, these will be the mainstays of your barrage.

The limited variety of songs have ensured that Bizarre Creations have chosen thoughtful music that genuinely accompanies the gameplay well. Indeed, the catchy music doesn't grate even after long sessions of gaming, something Geometry Wars was clearly not designed for. Of course, the option is available to use your own music, and I've found the electronic techno beat of the in game music to work well, so using my own music, I look towards that genre. The sound effects are powerful and have good impact, especially memorable is the bomb sound effect that beautifully warps the screen and muffles the music, before it returns, as catchy as ever.

The graphics are simple, and yet the games effortless use of eye catching colour draw the gamer unsuspectingly into the games great arcade roots. The fast action is accompanied well by enemies that blast into millions of wonderfully bright explosions and with thousands hunting for your pixellated ship en masse, things can get very hectic, and a *** of a lot of fun.

At only 400 Microsoft points, this is great value for money. The achievements will take some time in getting, and the leader boards will have you fight tooth and nail for every rank you gain. I personally keep coming back to the game for it's simple design and addictive gameplay. Highly recommended.