While I'm aware that European influences have survived decolonization in many parts of Africa, it's clear that the native ethnic groups retained far more of their culture and their language than their counterparts in the Americas. Africa is not a "Europeanized" continent, whereas every country in the Americas speaks either English, Spanish, or Portugese as their primary language. I suppose one exception to this would be South Africa. I'd also be interested to know why it, specifically, has retained so much European influence.
Three reasons: First, America was colonized much earlier. Apart from some trade posts, Africa had remained mostly uncolonized until the 19th century. America was being steadily colonized since 1492. Second, Native Americans were very weak against European diseases brought by the colonizers. This meant entire tribes and civilisations died, leaving large areas uninhabited. This is especially true for South America where both the Aztec and Inca empires were uprooted and destroyed by the Spanish. Africans, on the other hand, were used to all the diseases Europeans had and had some of their own, such as malaria. Only when the cure for malaria was discovered in the 19th century were Europeans able to colonise Africa. Third, Africa was colonized in an entirely different fashion to America. Large numbers of Europeans came to America and settled there. In comparison, only small numbers of Europeans came and settled in Africa. African colonies were controlled economically, by giving power and money to local rulers in exchange for goods and resources.