GameTrailers has the official trailer (with a cameo from Bob The Voice-over Guy) of Armoured Core 4 & it looks pretty nice with a combination of in-game footage & FMV sequences.

I’m a Gundam man myself although I did have some fun playing both Zone of the Enders games on PS2 but I haven’t really enjoyed these mech fighting games that much.

Official Armoured Core 4 Trailer