It's worth mentioning that this is a beautifully realized game universe. No, it's not quite as colorful and dynamic as Star Wars - honestly, nobody's ever going to beat light sabers, wookiees, and Leia's slave-girl genie bikini. But Mass Effect's version of the galaxy is still captivating. It looks graphically stunning, andthough tech-heads will notice that textures sometimes pop in asplit-second late, nobody will really care.
The game world isn't quite as wide open as we'ddreamed - you can't land on every single planet (and those you can visit are often a bit barren), and you can't randomly steal things or kill civilians and get arrested like some kind of sci-fi Oblivion. But the staggering amount of attention paid to details and backstory - how hyperspace works, why the elcor aliens talk funny, what each planet is made of - makes the overall experience feel much more rich, realistic and satisfying.
The main critical path is 20-30 hours long, though it feels a bit shorter - probably because the main missions are quite long, so there aren't as many as you'd imagine. Optional side quests should supply you another 20 hours or so, and gave us a fun, Star Trek-like sense of wonder and exploration. They usually take place on different planets and you often have absolutely no idea what you're going to see or do. You might find yourself ambushed by a giant worm on a desert planet, trying to defuse a nuclear warhead in an abandoned mine shaft, or frisking space monkeys on a lush-but-poisonous paradise world as you search for a lost data module.