Heed the advice of a die-hard old school Armored Core veteran: Wait for Armored Core: Last Raven.
Compared to previous stellar performers like Armored Core: Master of Arena, Armored Core 2, Armored Core 2: Another Age and Armored Core: Nexus; Nine Breaker is a stripped down bare-bones performer which is barely Armored Core: Lite. The game strives, perhaps unintentionally to evoke feelings from Armored Core: Master of Arena, arguable one of the better AC games, but it pails in comparison to the PlayStation cult hit. Master of Arena was fun to play and had a great story to it that played out not only in its missions but in the Arena too. Nine Breaker is frustrating at its worst and offers no storyline to keep you entertained, just mounds and mounds of arguably superfluous training missions.
Nine Breaker's training side puts your skills as an AC pilot to the test, but it tends to go overboard sometimes and expects a little too much of you. Freshman players can be easily overwhelmed in tests that quite jarringly go from easy to challenging to near impossible as the game goes on. Even veteran players who should already know all the moves needed to breeze through these tests can easily be caught off guard and sunk in some of the nastier levels like Defence: Evade lv. 5, Technic: Spacing and Proper Distance and most of the Overall category. The game compensates you for your time and effort by rewarding you new parts for your AC, but its really a hollow gesture by the time you've pooled 3 hours into just trying to pass a nearly impossible test like Defence: Evade lv. 5.
Where Nine Breaker shines, albeit dully, is in its Arena mode. Over 200 opponents of varying difficulty wait to challenge you here. Unlike pervious AC games however, Nine Breaker's Arena is somewhat unconventional; instead of fighting your way up an Arena ladder opponent by opponent you instead fight against other opponents in a class and earn points, when you collect enough points you can then fight in special matches in order to advance. This happens over and over again until you come face to face with the #1 Raven in the Arena, sadly its not even Nine Ball as the game's box art would mislead you to think, he appears in a training mission only. Regardless of its set up, Arena matches are perhaps the funnest part of the game. Nine Breaker's AI is challenging and pretty smart to boot, you need to be on your toes to beat them, unlike your training opponents which require you to be near superhuman. Again you earn AC part rewards for completing various requirements in Arena mode, but again the gesture is rather hollow and lacks a sense of real accomplishment.
Nine Breaker on a whole is rather disappointing compared to its predecessors in the Armored Core canon. Like other reviewers have accurately noted, it lacks real and engaging content and a sense of accomplishment. If you are a glutton for punishment then this game's right for you, but if you are bothered by stressful situations then skip it.
Armored Core: Last Raven is coming, hopefully sometime next year, (though Agetec does seem to be getting exponentially slower in their importing process). If the initial impressions from its Japanese release are any indication then it appears that it will be light-years ahead of Nine Breaker in all possible respects. Save your money for Last Raven, its going to be a much better game, perhaps the best Armored Core to date. If you're *really* interested in it then wait a few months for it to decease in value before picking it up because you'll probably kick yourself if you buy it at retail price.