Great Creative Tool! Hopefully they'll make more software like this!
First of all, the fact that you're not able to save anything is a shame. But, for those of us who already dabble in the digital music realm, hooking your DS up to your PC is more than likely a task that you already conceived of doing when you got this game. Being able to just jack it in and record using a handful of free software floating around on the internet is a great way to be able to capture the creative moments you may have with the game.
I would recommend this for any musician who enjoys dabbling with even the most simplest of electronic music devices such as keyboards or drum machines. If you enjoy music and have a nack for finding musical or rythmic patters and enjoy the interactivity of the DS, chances are you'll like Electroplankton.
For other gamers who enjoy an interactive experience, maybe borrow it from someone you know who has it...or if you're lucky see if you can rent a copy from GameFly or Gameznflix.