Seasons are controlled but the axial tilt of a planet relative to its orbit. Earth has an obliquity of about 23.5 degrees. This tilt causes the extremes of our seasons. "Along with daily rotations, this moderate obliquity ensures that the temperature differences between the coldest polar and hottest desert regions are not too extreme.". If a planet has a low axial tilt, then the planet might not be habitable because the planet's temperatures do not fluctuate. If a planet has too much of an axial tilt, then the extreme temperatures can also hinder the survival of life.

This is called the "Goldilocks"zone. The planet can not be too hot or too cold, but has to be just right. Simple life, however, is able to survive within these conditions. Some organisms and bacteria can ride out the extreme temperatures, but complex life would not be able to live on. 


http://www.space.com/14509-alien-planets-planetary-tilt-search-life.html