Iran, Russia, United Arab Emirates, China, France and the US are country level actors that I know of. I have no doubt there are more. Some of them try to keep the interests of Africa in mind, some are straight up looting (if you make money from a mine but use your profits to improve the area is that looting - this is a complex topic that depends on details)

Many countries are run by a dictator (often their top military general) who run the country for their own gain. Sometimes these dictators are natives who grew up as elite in the country, but none care about the people. Even where the country is a democracy, often the leaders are using corruption to ensure they win elections and then they run the country for their own gain not the people.

Note that I didn't put companies in the list. While there are companies involved, they are all hiding between a country in some way and if you reform the country they are powerless.