To understand how Wing Tsun became so unique, it may help to understand a bit of its history.
According to legend, Wing Tsun was developed by two women. The first was Ng Mui, a Buddhist elder who was skilled with an older method of kungfu that required strength and power and long, low stances and was not at all suitable for a weaker person who would be faced with larger, stronger attackers. After fleeing the Monastery where she lived, which was under attack, she traveled to a mountain top to meditate and was inspired by observing animal movements. However, that seems to have changed in that the resulting techniques do not resemble the animal movements of her former martial art, but, instead, were adapted for use by the human body. The second woman further refined it and it became named after her. The woman was Yim Wing Tsun.
Today, Wing Tsun is less complicated that other kungfu styles. It enables using the force of an attacker. It uses much faster pathways in its strikes and kicks. It emphasizes practical movement and not choreography.