Omega's an epic - so large that even during our lengthy playthrough, we barely scratched the surface. What we did play was, amongst other sections, a ripping combat scenario against new enemy type, the Rampart Mech. Built by Cerberus, the Rampart Mechs primarily control populations and disperse crowds - essentially, riot vans on legs. As well as being heavily armed, they're also heavily armoured, blessed with the ability to pass harmlessly through force fields that can instantly kill organics. That's hardly playing fair, but then, Omega's meant for battle-hardened ME veterans who've braved numerous encounters. It's a made-to-order challenge with new threats and faces, even for those who've sunk a few hundred hours into the series.