Much like the justification for killing Shinn Asuka's girlfriend in Gundam SEED Destiny, this game confuses the fuck out of me. The Gundam series is not known for its stellar writing in most series, and as such, the English name for the series should have been "Cool-Looking Mechs Fighting For Vague Reasons". That tone seems to carry itself into the games, which often boil down to fighters or brawlers more often than not; if you're looking for a mecha game series with a little more point and purpose to it, the Super Robot Taisen series is for you.
I'll start by saying that I don't speak Japanese, although I have been called baka-gaijin by white people before. As such, my analysis of the plot and structure of this game could be entirely wrong - if that's the case, please correct me, as English-language guides for this game seem to be equally non-sensical.
I don't have much of a history with the Gundam series, but I'm a fan of sorts - I loved staying up late on Friday nights to watch Gundam Wing on YTV as a younger gentleman. I recently re-watched it, and the pseudointellectual babbling about the philosophy of war made me raise an eyebrow or two (but don't misunderstand - I did really enjoy that series, especially the human element of it). I watched Gundam SEED Destiny but not Gundam SEED. I tried watching 00, but nothing that happened made any sense. Still - I love building the models, and I'm a HUGE fan of the art style and creativity of the mechs in every series.
So let's get down to the game. First thing you'll see is a music video with Gundam set to a Gackt song that would fit right in on an early Tony Hawk game. You will hear this a lot. It's equally gross each time.
The game modes are pretty easy to figure out - there's a bracket-style arcade mode that'll be easy to figure out for anyone that's played a Darius game before. The path you take in this mode will determine what final boss you will face; there are about 8 different ones from what I can tell. You can play this one- or two-player. There are also several online modes, which I'm not too eager to try out (because I'm bad at this game).
That gameplay is similar to those DBZ Budokai or Naruto Ninja Storm games - you can freely move around a 3D plane, and it sorta works like a battlefield with a tons of mechs on it. You can choose from a hundred or so mechs (not just Gundams) spanning what might be every Gundam series. This is where my biggest gripe arises: The roster isn't at all balanced. The game MAY be designed this way, as there's a cap on points that limits the number/type of mechs you can use, but in terms of the arcade mode, it's a huge pain in the ass. When you start your game, you're saddled with another random mech from the roster. This could be a throwaway Zaku that's nearly useless in battle, or it could be Wing Zero. It's a crapshoot. This can make a massive difference in the ultimate battle, since that Zaku will die several times and ruin your efforts to win. Just the same, you could be saddled with a mech that wipes the floor with your enemy, giving you a win without much effort. It feels like this game was designed to work in such a way that you can use, say, one great mech and several lacklustre ones, but this never happens when you play solo.
Another major complaint I have is the core gameplay itself - because the levels are so huge and because there's so much going on, it's really hard to hit your enemies. The computer AI will randomly attack anything on your team, meaning they dash around the map in erratic directions. It's REALLY hard to land a hit. Just the same, you'll die a lot for the same reason - while you're trying to chase down one enemy, other enemies will shoot you from behind. Their accuracy is amazing. I have beaten the game, but winning a match feels more like luck than skill. You button mash, hoping your attacks land, and when the match ends, it's not clear if you've won or lost until the game tells you.
As alluded to with the roster, the fanservice seems to be amazing. There's 2-4 mechs from each series (or movie) represented, and you're treated to a short cutscene homage to the series you've selected from before you start the game. It's kinda cool. Trouble is, the game seems to assume you know how each mech works - you don't have a default set of controls at all. Some Gundams are melee only, some only have ranged attacks, some are slow to the point of immobility, and not all of them can fly. If you select a mech you're not familiar with, it's really difficult to figure out how to use it.
Again - maybe all my gripes are explained better for one who can read Japanese. For me walking into it, the game is A LOT more complicated than videos would make it seem.
So what's good about this game? Well, the graphics are really great. The mechs all look accurate, they move and attack as one would expect... It's well-done from a technical standpoint. The controls are pretty tight, and murdering mechs is really quite fun. The overall art style is really cool too, with lots of cool wire frames, "broken crystal" looking designs... Mechs with glowing parts really gleam with loud neons as they should. Mechs made of simple metal look properly efficient and battle-worn. It's a gorgeous game. I just can't figure out how to play it well.
Oh, and I think there's a plot or something - something about a mech analyzing battle patterns of other mechs and designing itself accordingly? That's the final boss. I don't think it's explained why mechs from universes that can't possibly be the same are in the same game, but again - yo no hablo Japonaises.
You want a rating now? I have no idea. 7/10? Something like that. I mean, the game's cheap - it's like $15 in Japan, probably around $30 to import it via eBay. If you like Gundam stuff, it's worth a look. This game could be a 10/10, I could be missing something super-obvious to a Japanese player that makes the game much more enjoyable. But playing as a Canadian dude with no grasp of the language, it seems like a daunting game to tackle, with aggressive learning curve and little incentive to get good.
If you're into this sort of thing, check it out. If you're not, I don't think you're missing anything revolutionary.