Mass Effect is an absolutely amazing game. In fact, as regular readers will know, it's my 2007 game of the year. And so it was that I spent the 400 MS Points on Bring Down the Sky, BioWare's first DLC for it's stupendous sci-fi RPG. Is it worth your hard-earned cash? I've blasted by way across Asteroid X57 and completed the scenario to find out.

The premise is this - X57, an asteroid in the Asgard system of the Exodus Cluster, has been overrun by the bitter Batarians, an alien race talked about in the main game but never seen. The Batarian fanatics have taken control of a science installation on the asteroid surface, held a number of researchers hostage and have commandeered three massive thrusters that were being used to reposition the hulking rock for use as a space station. If that wasn't enough to get the Galactic Council hot under the collar, the Batarians have redirected the thrusters and sent X57 on a collision course for the nearby planet Terra Nova, a human colony with a population of four million. If X57 hits the planet, that won't just be the end of the colony, it will be the end of the planet itself.

And so it's down to you as Commander Shepard, the only human spectre in the galaxy, to sort the mess out. Once you've downloaded the DLC you'll see X57 highlighted on the Normandy's Galaxy Map. Whatever your level, as soon as you gain access to the Galaxy Map (achieved after becoming a Spectre on the Citadel) you'll be able to tackle the Batarian threat. But if your last save is right at the end of the game, perhaps on the final planet or just before the last boss, you'll have to start a new career and work your way through the Citadel before you can try it out.

Graphics wise, X57 is a barren, cold lump of grey rock set against a jet black sky, mimicking many of the game's asteroids. It's not a planet, so there aren't any fancy weather effects or environments to enjoy. But what it does have is the giant image of Terra Nova itself, which takes up almost the entire background from one angle. Add to this the fact that from almost anywhere on the surface you can see and hear the thruster fire from the three torches as well as bits of asteroid floating about as X57 hurtles towards the planet, what you end up with is a real sense of immediacy and gravitas. It feels epic, exciting, heart-thumping and rekindles memories of divisive Michael Bay movie Armageddon.

Bring Down the Sky works just like any optional Mass Effect side quest, so it's not essential to the main story. One of Mass Effect's main criticisms is that its side effects are, well, boring. Bring Down the Sky certainly isn't boring, but it does include lots of messing about with the Mako, the game's much-maligned vehicle. The DLC makes no apology for this, and, especially on harder difficulty levels, fans will find the thing as frustrating as ever to control. So, like in many off-world side-quests, you'll be moving back and forth from a position as far away as possible from enemy turrets and drones, dodging and boosting over enemy fire until you've eliminated every threat and wrestled each of the three thrusters from Batarian control. This is as fiddly a process in Bring Down the Sky as it is in the main game proper. Looks like controlling the Mako's cannon independently of it's movement will have to wait for Mass Effect 2, or Mass Effect on PC.

You'll be fighting the Batarians, a somewhat funny but evil-looking alien race.

Inside the surface structures you'll get the chance to go head to head with the Batarian's on-foot, as well as get a flavour for their personality, culture and history. They're Mass Effect's most obviously evil looking race, with four eyes and razor-sharp teeth. Part of the fun of the mission is finding out exactly what their beef is, so we won't spoil it here. Suffice it to say, they're willing to do whatever it takes to make their point - including killing four million innocent people. We will say though that after finishing the mission we felt a little underwhelmed by the story.

In combat you'll find the Batarians act much like the other enemy humanoid races in the game, for example the humans and Krogans. Depending on the difficulty and your class you'll be employing similar cover-based tactics that proved so successful in the main game. And, as you'd expect, the enemies will be scaled depending on your level, theoretically presenting a considerable challenge whatever your squad's level. Again, this is somewhat of a let down - those looking for an enemy against which they'll have to employ new tactics will be sorely disappointed.

Thankfully the asteroid's main installation isn't simply a carbon copy of the building used for almost every single side-quest in the main game. It's actually quite an impressive sight, with tight corridors leading into a large, centralised research room with multiple levels. It's in here that Bring Down the Sky really kicks off, and is at its most heart-thumping.

One of the most pleasantly surprisingly things about the DLC is the moral conundrum it presents towards the end. Throughout most of Mass Effect the decisions that lead to Paragon points and the decisions that lead to Renegade points are blatantly obvious. In Bring Down the Sky the big decision is a genuinely difficult one - I wasn't sure which choice led to what - and that was refreshing.

While overall the DLC kept us entertained, the optional assignments are boring - discovering the bodies of three researchers scattered about the asteroid surface isn't what I'd call adrenaline pumping. Turning on a radio transmitter for no apparent reason isn't going to set the galaxy on fire either. Because of this, and the fact that Bring Down the Sky doesn't really add anything new to the Mass Effect mix, we reckon it will be for completists only.

Bring Down the Sky is a solid, at times intense start for Mass Effect DLC. It's better than many of the main game's side quests but, essentially, it follows the same format. We have high hopes for future, inevitable DLC - Bring Down the Sky offers an additional 50 Gamerscore points, leaving room for another four sets of DLC if they follow suit. Next time though we'd like to see something on a planet surface, on a greater scale and with more story elements - akin to one of Mass Effect's main story planets. That, and perhaps some more special abilities. That would be worth paying extra for.