I got the chance to play this game around a month or so ago on an friend's japenase PS2 with import copy of AC3.
Keeping in mind I never have played an AC Game, expect for the demo for AM2. I found this game to be very dull, and the mission descripitions were often much more enteirtaining than what the actual mission was like.
Mindless objectives as, defeat these guys, then move here, defeat this guy, repeat process 10 times.
What the game lacks in gameplay it makes up for in the beautifull graphics, everything is very detailed even down to the jet trails.
Also it is very cool to customize your Mech with I swear hundreds of different parts. But yet, 70% of the gameplay as editing the mech unit and not played it.
Godo game, but I don't see it fitting a 50 USD Price Tag.