What makes a remake? Not even developers really know.

Washington Post - Technology News 

However, the level of rebuilding undertaken by the developers exceeded the usual expectations of a remaster. While "Saint's Row: The Third Remastered" largely kept the game's mechanics the same, the scale of the graphical overhaul was akin to that of a new game. A traditional remaster is usually relatively straightforward, and involves cleaning up, improving, and tweaking existing assets. In "Saint's Row: The Third Remastered," however, a lot of the original assets were thrown out, with new (but identical-looking) ones built in their place. For example, each vehicle had new individual undercarriages, engines, interiors, lights, grills, and bumpers redesigned from scratch for a new engine, designed to look like a more polished version of the original model.