I have flown on Air Mauritanie, which is considered one of the better airlines in West Africa, from LPA to NKC via NDB. The flight was short, but a hot meal was served and edible. Seating is free. There is a separate J class.

Their flights are always a bit late, say an hour or two, and mine were as well. The planes (F24 and 737) were old and shabby and there were no announcements in English, but nevertheless the flight went OK and I would fly them again if I was to travel to Nouackhott again. Which might be the case taking into consideration that it was actually quite a nice place in its own right, though it's somewhat bizzarre.