Gameplay-wise, most Armored Core games have been only thinly distinguishable from sequel to sequel. You're a mercenary with a great big mech, which you can customize to your heart's content. Last Raven does bring a few more sandwiches to the picnic, but it's really just another small upgrade in a series that runs short on big ideas.
Since the developers know that their fans are hardcore as hardcore gets, metalheads are unceremoniously dumped in the deep end with no tutorial. You do get two options this time around: you can challenge a ladder of over 30 head-to-head arena bouts or explore a storyline that branches based on which of the over 70 missions are completed. The tale unfolds through e-mails, text-based reports and the most rudimentary of in-engine cutscenes, though, so don't let the slick opening movie fool you.
While the campaign mode is certainly welcome after the previous AC game's arena-only focus, its missions and level designs have a dull, prefabricated feel that makes it hard to get interested. Stark environments are granted only rudimentary details and texturing, and populated with helicopters and pointless human specks that are only barely identifiable as such. Enemy mechs look better, but they tend to just hop around, firing maniacally. The game runs well, but the hit to the detail makes it hard to care. Worse, the objectives - protect this bland base, accompany that easily destroyed gimp - are executed with zero imagination, and no regard for any consistent difficulty level.