Other than what the rest have said, it appears that your character may get stuck in the ground from time to time when walking. This is probably caused by using tile colliders for the map without adding a composite collider. A composite collider basically merges all colliders in the object into 1 single collider. Currently, instead of the entire map being 1 single collider, each tile has their own box collider, and your character may get stuck between each collider when moving across them.