Narrow Peaks is the 17th Expert stage in Super Monkey Ball 2 and the 36th Expert stage in Super Monkey Ball Deluxe. It also appears as the 146th Ultimate stage with continues and the 186th without continues.
There are two paths to get to the goal.
Path A: this is the easier of the two, and should be taken if you are new to the game because it has wider peaks. After you go across the first peak from the starting platform, go across the peak to the left. The peaks get narrower as you get closer to the goal. Continue on to the peak straight ahead. Go over the next peak on the right after you have positioned yourself on the flat platform. Collect the single banana, and roll along the long peak straight ahead and into the goal.
Path B: This is very difficult, considering how narrow these peaks get. After crossing the first peak from the start, go across the peak to the right. Position yourself on the flat platform, and roll quickly over the peak straight ahead. Collect the four banana bunches. Position yourself again on the flat platform, making sure you are completely in-line with the narrowest peak of all to the left. Roll across with enough speed, and collect the banana bunch and the single banana. Roll along the long peak straight ahead and into the goal.
Roll to the back of the starting platform. Then, go quickly toward the first peak, bouncing off the angled sides of the platform, and fly straight across the gap to the platform with the single banana. Balance yourself on the peak that leads to the goal.
In Banana Mania, it is possible to clear the gap without rolling back. In Story Mode, pressing forward at just the right time (roughly halfway through the fall of the small bounce from spawning in) will allow the player to clear the gap and roll straight into the goal by holding forward. The timing for this is fairly tight, but consistent. In Challenge Mode, holding forward immediately will cause the ball to bounce up off the edge of the platform on the other side. From there, returning to neutral for a bit and then continuing to hold forward will allow for completion.