Not much is currently known about the game other than the brief description from the ESRB website below.

This is a rock climbing game in which players must climb up various formations within a time limit. Players navigate rocks and walls by grabbing onto divots and edges and positioning themselves to ensure they do not fall off.

It's also rumored that the game will make use of the Wii Balance Board, although nothing has been "officially" confirmed as of yet.

We'll have more information on Rock N' Roll Climber as it becomes available, as well as a full review when the game hits the WiiWare service.

Source: ESRB