Let me start off with saying that this review is just my opinion and that I am a Gundam fan.
Sound: The best sounds come from the MS moving, the Japanese voices, and the music but the music doesn't fit in a OYW game. Beams sound weak and nothing like what they sound like in OYW Gundam shows. Machine guns sound like infantry guns and sound weak. The english voices are also terrible.
Replayability: For me this is low as I had unlocked almost everything on my first play through. This varies depending on how good you do in missions and how many missions you beat.
Graphics: The MS, tanks, fighters, and other military vehicles look really good. The environment looks fine. Not the best I've seen but not the worst either it looks worst up close. Overall: I think it is better than some older Gundam games but not the best.