Just... A plastic cartridge which goes "beep" a lot.
Well hummh... I only rented this so I was lucky not to spend any more money on it. For me Electroplankton was funny for the first five minutes, but then it became... A cartridge without any value or content. A small piece of plastic full of beeping and obsolete sounds (you know, DS isn't a fancy boombox...). I could just open up a tracker software on Windows and make it beep randomly. that wouldn't even cost me anything, plus it can evolve into something deeper, something saveable, thus making it more worthwhile.
I now know what kind of sounds those plankton things make. It took me no longer than 5 minutes to hear the sounds. And that's all the content there is. I guess I'll try this one again the next time I'm heavily drunk, it might work better!