Labyrinth is World 10-6 in Story Mode in Super Monkey Ball 2.
The stage looks like a nightmare because it has many ramps, platforms, and dead ends. The goal is on a high platform near the starting point, and there are some banana bunches dispersed throughout the maze.
There is only one goal, the blue goal. Go up the ramp on the left. Head straight toward the left edge of the stage. Fall down onto the green tiles. Turn right so that you are heading "north." Roll at top speed toward the gap to clear it. Turn right at the first intersection, go up the ramp, and follow the path to the last intersection. Turn right to drop down, roll up the ramp, and head straight until you come across the last ramp on the right (it should be white-lavender colored). Go up the ramp, and quickly turn right until you get to the corner edge of the magenta tiles. Turn around so that you are facing the dark green-blue ramp that is leading up to a wall. This part is very tricky. Roll from the corner onto the ramp. As you get near the top, move to the left so that the ball gets over the bump in the corner. Follow the path "south" (you should be able to see the beginning in front of you), drop down onto the goal platform, and head in.