Soft, soft sand: Good for skidding out on your bike, if you are into that kind of thing. Probably my least favorite kind but generally identifiable from a short distance.
Gravel / small rocks in dirt: Not too bad for riding, a little bumpy, but doable. Some propensity for hidden larger rocks.
Dirt strewn with large rocks: Dislike. If you don’t watch out and hit the rocks at a good angle, you can get a jolt, or slide and shimmy of the side of a rock. Unpleasant
Paving stones: Generally good, but annoyingly, rhythmically bumpy. Good for a nice, fairly fast ride, with few surprise in the ride, but be prepared to share with cars and motos.
Hard packed dirt: Probably my favorite. Nice, smooth ride, decent speeds, generally less traffic. Some roads have potholes and other maintenance problems, and Small Rocks, Large Rocks, Soft, Soft Sand and Mud can also be present, sometimes unexpectedly.
Paved: Arguably the best surface to ride on, unfortunately there is only one truly paved road in Ouidah and it does NOT go anywhere you want to go. Trust me on that. And there are lots of cars and hardly any shoulder or side streets. Best avoided.
Mud: ever present after the rain, can give a nice hard pack to otherwise soft soils, but can get sticky and boggy and splashy depending on the composition. And it gets all over the floor when you take your bike home.