Nintendo Gal has got a hold of a prerelease copy of Electroplankton, and we've been comparing my import Japanese copy of the game from its original Japanese release to the US release.
The immediately apparent difference is in the packaging: the Japanese release came packaged as a DS game case in a blue foil box with bonus headphones while the US release is packaged like any other game, though the blue foil look is preserved. Headphones aren't included, though the headphones that came with the Japanese release are admittedly not high quality they're worth more as a collector's item than anything else.
Beyond the packaging, the game is a very faithful translation. The manual is identical to the Japanese version except the English text, preserving the hand-drawn plankton and illustrations which were no small part of the package's original charm.
Electroplankton fans fearing plans to transform the game into something entirely different for American audiences need not do so; the US release is simply a localization and seems to be unchanged. It powers up with the same orchestra tuneup sound effect, and provides the same modes and the same plankton as the Japanese release, simply localized.
Of course, we've been discussing this title in the forums for some time. If you're interested in hearing more about the title, check out Nintendo Gal's review, and of course our feature by James Burns, Inside Electroplankton.
The game releases January 9 and can be had via Nintendo's online store, and is also appearing in several other online outlets. To our knowledge, no retail availability has yet been confirmed.