Commander Shepard is the hero the Mass Effect galaxy needs. But he can't be everywhere at once in the fight against the Reapers. So ME3's multiplayer mode takes you out of Shepard's snug space-suit for the first time (barring ME2's titchy Joker section), plonking you into an enclosed space with up to three other no-names and asking you to fight against waves of enemy forces.
Those forces are mixed. The lobby host can choose to battle against Mass Effect's nastiest bad people, including the zombified husks of the galaxy-nomming Reapers, and Shepard's allies from the previous game turned definite evil, the Cerberus. Not only are you not-Shepard, you're also notnecessarily- human. ME3's multiplayer lets you play as Asari, Krogan, Salarian, Drell or Turian, too.
Scraps take place in small arenas, presumably lifted from the singleplayer game. They have the clean lines and futurecrates of the previous games' environs, but if the blue-tinged city wing I fought in was anything to go by, lack the main game's interesting RPG clutter. My battleground was built entirely for combat, and decked out with a convenient abundance of three foot walls.
I found sticking to these made my life a lot easier. Mass Effect isn't built for quick reactions: not-Shepard's turning circle is as ponderous as Shepard's, and the guns you'll be using are more gentle hose than precision tool. The exception is the heavy sniper rifle still as boomingly lethal as ever. For the first five waves of the eleven wave cycle, I hid behind an idle spaceship and squeezed off echoing headshots at targets chasing my allies. Only after wave six was I flushed from my hidey-hole, as my foes got bigger and gooier.
Then I was forced to fall back on my secondary powers. I played one session as a bog-standard soldier, his two abilities a concussive shot that knocked enemies backwards, and a shield boost to help out under fire. The other classes had less in the way of weaponry, but infinitely more enjoyable powers.
Mass Effect 3's multiplayer isn't as satisfying as its violent peers. More interesting is the 'galaxy at war' system. Embark on a multiplayer session and you'll level up your character. You can then choose to send him off to join the fight against the Reapers on the main game's galaxy map. Players who had otherwise completed 95% of the actions necessary for a 'perfect' ending may well find them bumping that 95 up to a nice round 100. But of course Bioware were keen to stress they weren't forcing people to play with their friends – the new multiplayer is a secondary skirmish, not the frontlines of the war.