Scale. It's the thing that sets Mass Effect 3 apart from its predecessors. Although the series already spans an entire galaxy, it's always felt like a series of linked skirmishes; tiny dents in massive, apocalyptic story. With Mass Effect 3, that changes.
Shepard and his crew have reached the tipping point: no more skirmishes - the Reapers are here, and nothing less than a universe-wide scrap is going to resolve this fantastic series. "Mass Effect 3 really is the pinnacle of the series - we've been working on it for eight years now," says series director Casey Hudson.
"This really is the main event..." To illustrate his point, Hudson directs us to the latest demo mission - Shepard and his crew attacking a Reaper base. In Mass Effect 3 the Reapers are tangible creatures, things that can finally be killed. Sure, Shep brought down a few during the attack on the Citadel during the original game, but that was within a cut-scene. Now you're fighting them on the ground via regular gunplay and more scripted boss-style battles.
The demo starts with Shepard killing off a couple of Cerberus troops (more on that later) before looking down into the Reaper base over a metal precipice. He paints the target with a laserdesignator and calls the Normandy in to drop some heavy ordinance inside.
Then it goes a bit wrong. Shepard is shaken off his perch and tumbles to the storey below - and it's here that he discovers that the airstrike wasn't nearly enough to wipe out the base. A giant Reaper ship seems to crawl out of the crater, and Cerberus troops leap up from the sides of the walkway. Uh-oh.
MIX AND MATCH
The regular Reaper troops will come in the form of abominations - creatures created by the Collectors in Mass Effect 2. We've seen artwork displaying mashups of almost every race in the universe, all with recognisable bits - Batarian, Asari, Krogan, more. They form ramshackle units, combining powers and behaviours to try and outsmart Shepard and his team. But we haven't seen them in the flesh yet - that's to come in our second demo.
For now we're here to pop Cerberus grunts, a much more recognisable enemy. You're fighting the might of the Illusive Man and the Reapers in ME3, and Cerberus have new weapons, more troop types, and a variety of heavy mechs... it hardly seems fair, but - as we see in the opening exchange - Shepard is looking lethal himself.
Forget the clunky cover-to-cover gameplay that Mass Effect has previously borrowed from Gears Of War - combat in number three is fast, varied and frequently spectacular. Shepard vaults over and around cover, flanks his enemies, suppresses them using a combination of weapons and grenades (no longer the sad discs of the original), and - when anyone strays too close - uses his new Omni-blade to stab a hole through their armour.
Despite the series' RPG roots, Mass Effect 3 is bearing all the hallmarks of an action/adventure game - an educated surmising which is cemented by the next slice of the demo.
Hurrying along the rim of the Reaper base, Shepard receives a message from Legion. He's found a way out - a massive hovering tank with a mounted cannon - so Shepard makes a dash for it, accompanied by Liara and Garrus.
They arrive as the Reaper emerges fully from its pit, and while his underlings make themselves comfortable inside the tank, Shepard climbs to the cannon to tickle the Reaper with its shells. It seems pretty ineffectual. Remember we were talking about scale at the start - this is it, and you're on the wrong side of the massive adversary.