As Dr. Phil would say, Godzilla Unleashed
has communication issues. There are two main modes: Story and Brawl. As the name suggests, Story is where most of the game's "meat" is. The main story revolves around crystals popping up and driving the world's monsters crazy (as if they needed much encouragement in the first place). Played all the way through, the Story mode isn't all that long and shouldn't take more than a few hours. Though the story is kept linear, each level has a more open structure, bringing the game's communication problem to full effect.
It all begins with the story, which never fully explains what the crystals are. Once you enter a mission, you are given several objectives that aren't all that clear. You can choose to fight the other monster or attack the crystals and try to free them. Everything is supposed to tie into some sort of "faction"-based system (and here I didn't think monsters had factions), but the system isn't explained well enough to matter. Eventually you'll find yourself ignoring mission goals altogether and just destroying things until the level ends.
This haphazard structure becomes slightly more frustrating when you get the chance to unlock new monsters. It is never clear how you should go about freeing them. I assume this was to encourage replay, but when the game isn't much fun in the first place, you'll probably just get mad that you can't unlock a certain favorite monster.
Brawl is a little more fun, mostly because it ditches the lame story and focuses on what you really want out of a giant monster game - beating up other monsters and destroying cities as Japanese businessmen run screaming for their lives. Brawl supports up to four players and features two play modes: Destruction and Melee. Destruction is all about doing the aforementioned city remodeling while Melee plays a little more like a fighting game and awards points for beating up the other monster. You can also create your own game parameters, which is a cool option.