As you can see in the reflections, Sketchfab's optimization damaged the Normal Map. I still haven't found a solution to solve this problem.
> If you add "[?image_compression=0](http://sketchfab.com/3d-models/auto-race-80s-handheld-game-835048164013473cb675841e27b67ee5?image_compression=0)" at the end of the URL, you can view the 3d model with the original textures.