Things Fall Apart, pt 1

Question: discuss if you think (Joseph Conrad's) apology was enough when compared to Achebe's text.

I don't think it's fair to compare these two texts in that way. Things Fall Apart (1958) was written half a century after Heart of Darkness (1902).
Conrad's book was the very first thing that had ever been written about the horrible treatment Africans were receiving at the hand of Europeans. It was groundbreaking, being the first critical look at imperialism in Africa. Though it might not have gone as far as Things Fall Apart, based on the time period it was written in, it was very controversial. Yes, Conrad could have been more sympathetic toward Africans as he commonly referred to them all as savages and didn't distinguish different tribes from one another, he still recognized crimes of humanity occurring. He didn't see them as complete animals like other Europeans did, though he did still place them lower than Europeans. Without Conrad's book, Achebe would not have had a precedent to follow.

I think that the destruction of the authentic African tribes and cultures was a horrible thing to do. White people were taught the "white man's burden." The white man's burden is that it is the job of white people to civilize indigenous people, and teach them the Christian religion and assimilate them to be like Europeans. That the white people must "better' the poorer ones. This meant they were completely indifferent to local culture and traditions. 

Though Europeans might have become rich in natural resources and money, it came at a great cost to human life and culture.