If you want something more descriptive than a simile, the Arkanoid site is cleaner and more organized than its Invaders counterpart (and it's also silent), but we think that may be because there's no "Extreme" in its title to live up to. Those who prefer trippy visuals and loud music on their web browsers, though, should head on over to the SIE page (consider this a sound alert for those of you in "not safe for audio" workspaces). If you've visited the Japanese website for this title before, you'll know what to expect, as it's exactly the same.
As it stands, there's not much to do on either site except read about the games. We were hoping that little demos or browser games would be present, but alas, our wants were denied.
At least we'll see the real things in only two weeks.
Gallery: Arkanoid DS
Gallery: Space Invaders Extreme
[Via press release]
Source: Arkanoid DS official website
Source: Space Invaders Extreme official website