Ontamarama impressions at Nintendo World Report.

"Leave it to Atlus to bring a quirky Japanese rhythm game to America. Already released in Japan as Ontama: Onpu-tou Hen, Ontamarama is a music game that requires multitasking of the Nintendo DS touch screen and D-Pad to play along with the beat of a Japanese soundtrack. A series of colored panels scroll across the top of the touch screen, indicating which direction to press on the D-Pad. The rest of the touch screen fills up with colored slime-looking objects which cause the similarly-colored scrolling panels to fill with a solid color when tapped, increasing their score value. Some panels are larger and require multiple slimes to be cleared from the touch screen to become filled. As a shortcut, you can draw a circle around a slime group that's all the same color to clear multiple slimes at once."

Full Source: Nintendo World Report