BioWare has seized the chance to fix a few of the tingling annoyances with the original game. The inventory and item-management system has been completely redesigned, apparently, although it isn't ready to be shown yet, and the comically slow elevators of the first title have been replaced with fancy neon-wireframe animations of you zipping from one location to the next - a dashing bit of misdirection, perhaps, but one that now covers some significantly faster loading.
More importantly, the dialogue system has been tweaked. Conversations and choices are now integrated much more smoothly into the shockingly stylish cinematics, and the butting-in system that was hinted at but never delivered in the first Mass Effect has been implemented, an occasional option to cut someone short now available whenever a left trigger symbol pops up. It works wonders in terms of making the exposition edgier and more natural, but be careful wielding your new powers of interjection: sometimes you'll find yourself racing in with nothing but a snide rebuttal, but on one occasion in the demo, Shepard ends a chat by pushing his conversation partner out of a skyscraper window.
Fighting has also been ever so gently retooled. The power wheel is still in place for selecting guns and biotic attacks, but you'll no longer need to pause the action to make selections. Weapons have been bolstered with nine new classes, including heavy options like a chunky new homing rocket launcher, and there's a raft of new biotics, all of which play on the improved physics engine, which sees the demo battle, taking place on the roof of a giant skyscraper, playing out in an impromptu pinball session of explosions, forcefields and cart-wheeling corpses. Team tactics are now contextual - point one of your squad at an enemy or cover and they'll know what to do - and there's a new body-part hit-detection system too, which allows you to take a robot's head off in a shower of sparks, or cut someone's legs out from under them.
Finally, the exploration element has been filled out. The galaxy no longer closes for business when the shutters of the story come down, and you'll have an added impetus to explore this time around. Along with scanning planets manually for a landing spot by moving a cursor over the surface, BioWare promises you'll also be visiting a greater variety of worlds, suggesting that you won't spend a lot of your free time touching down on a succession of differently coloured ashtrays.
With the rough edges knocked off the mechanics, and a lot more skill on display at handling conversations and framing the action, Mass Effect 2 seems to be balancing refinement with continuity as it heads to release. BioWare feels that even if you didn't play through the first game, this is still an ideal jumping in point, but more exciting is the fact that seasoned travellers can import their old saves wholesale, leaping into a narrative that acknowledges and incorporates every moral decision, every team-member death, and every unplanned burst of casual sex. Of course, that may mean you're stuck exploring the stars for a second time with a face like an ageing sixth-form college lecturer, but at least you've only got yourself to blame for that, eh?
Mass Effect 2 is due out for PC and Xbox 360 in early 2010.