Just finished the demo. The game is basically Armored Core 3 with giant bosses. There was only one boss in the demo, but he was fun to fight. He had a giant laser attack that you had to dodge. Oh and he hopped around a lot. You can destroy weak points to get rid of his ability to jump around, or shoot lasers. If the rest of the game has bosses as good as that I'll be sold.
The graphics are good in spots, but kind of PS2-ish in others. Trees had like two alpamaps making up their foliage, which is something I haven't seen since GTA4. Ears looked really blocky on the character models. Hopefully this gets cleaned up before release.
Sound was fairly good, but sort of repetitive. Voice acting was ok I guess. A few characters were borderline annoying.
Controls are solid, and infinitely better than the old Armored Core controls. Locking on with missiles feels good. I was a bit disappointed that the demo didn't really have a shop for upgrading your mech. Oh well. Still looking like a good game so far.