For 30$s and no saving this game is not worth it IMO.
It is (was?) $35.00 new.
I preordered it and got it on the US release date. Have I played around with it much since I first got it? Yep. Does it suck that it doesn't have a save feature? Sure.
However, this game is something unique. It's nice to just sit back and chill out trying to make some cool sounds. It's good when you're trying to relax. I often play it before I go to bed. Uniqueness is something that I'm willing to support.
That being said, the game could have easily benefited from a save feature. I'm really not sure why they didn't include it. It's certainly not taxing on the DS system resources, and I'm sure they could have had room on the game card to do so. Hell, even being able to save a couple of tracks would be better than nothing.
So, I guess that I agree with the original post. Cool and fun idea, but could have used a bit more polish.