It's not a bad game, it's just that it's not an actual game, a it tech demo, a game that show's you what the DS can do.
I mean, it has a score system, it has fine graphics, but honestly, it should've been worth 15$, because I hate the fact that I spend 25$ on this, but if your one of those people who just pick's up a game and play's it for about 5-10 minutes, than this shouldn't disapoint, but there are a lot of better ganmes.
Now, I'm not saying that it's bad, I don't think I ever played a DS game with Stylus control's as good as this, the control's for this game are excellent.
but I do not reccomend it for Yoshi fan, stick with Yoshi's Island DS, If your a DS game collector, than I suggest you get it for about 10-15$, don't pay a lot for it.
but like I said, it has perfect controls, good graphics, but it's not an actual game and it has NO replay value AT all.