Adrenalin inducing; great two-player cooperative. Frenetic. Galaxy mode adds challenges. NDS mode not revealed yet.
Different enemies have different behaviors, which demand different movement & shooting strategies.
Cooperative mode changes a lot of your strategies as you create crossfire which changes how you can handle enemies subtly but dramatically. After a few hours you and your partner will begin to "feel" what to do to support each other, and that's an incredible rush.
CONS: =======================================
As always, the game gets confusing. You die because your eyes failed to track something a lot - the trick is avoiding those situations as best you can by managing the enemies.
It's very hard.
Graphics might not be for everyone.
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This is a game that works well for the loner hardcore gamer as well as the hardcore with friends. It is too much for casual gamers to handle very easily - my 10yo daughter loves to sit down with me and play, but my wife & my 8yo daughter aren't even tempted to try it.
The game offers new modes which are neat: the galaxy mode, like Super Mario Galaxies, offers different worlds with unique layouts that alter how you play them. You can choose many (if not all) galaxies from the outset, which is nice.
There is an NDS option but I don't have the NDS cartridge and can't track down anything definitive about what that does. Apparently you can "unlock additional content." That's not nearly as exciting as "you can have your friends with NDS's play with you and one other on your Wii." So it's not about interacting, it's about getting rewarded for having both copies. Sad.
However, $40 (at EBgames.com) is a tad steep for a game of this type. You can't explore or spend hours immersed in a story - it is strictly a matter of learning how to play better and having fun with the different scenarios.
That said, I can't find many faults with the playability other than the same thing Geometry Wars has always suffered from: it's difficult/impossible to track all of the objects on the screen and, ultimately, it's a flat 2d space shooter.