^^To be honest, I'm not surprised. I have been noticing quite the decrease in new DS titles in comparison to new 3DS titles. I think Nintendo has pretty much stopped with the DS and are now fully focusing on the 3DS. So yeah, no more DS stuff. Sorry!
However, considering first impressions, I'm not surprised this is 3DS exclusive. The amount of fluid animation in this game would be too much for the DS to handle. The DS can only handle so much and this game goes well beyond it.
However, to me, the graphics are at the "uncanny valley" point for me. It's better, but it's just not all that eye pleasing to me.
That being said, anyone who's played Professor Layton before should be quite familiar with this new game. It is more focused on the touch screen then the previous games, but other than that, it's pretty much the same gameplay wise.
As for the story, it is pretty good so far. Plenty of mystery and it'll definitely keep me engaged until the end.
So yeah, save for graphics, first impressions are good. I'll be looking forward to all this game has to offer. I've got plenty to enjoy on this one.
See ya later!