Sine Wave is a curved line with 2 major curves the monkey has to overcome. The stage has railing on the sides for ease. It starts on one end of the path and goal lies on the other. This is a stage for the player to take on the turns of these floors, similar to Elementary in being more of a tutorial stage to newcomers.
To get through this stage, simply go straight and turn when needed to. It is not hard to fall out, but do be careful because there is a possibility you could. Nevertheless, this stage should be quick to handle to get used to the controls and such. Make sure to collect the bananas easily available on the trail if you prefer.