Here’s a comparison for Final Fantasy XIII between the Xbox 360 and Xbox One X version running at 4K resolution.
Final Fantasy XIII trilogy is available now as part of the Xbox One backward compatibility program. It supports a 4K resolution on the Xbox One X and looks amazing on it. Thanks to the amazing work done by Microsoft in emulating the original Xbox 360 games on Xbox One, it is also possible to play them essentially as a remaster and having them render a high resolution of 4K.
This was achieved in Final Fantasy XIII trilogy as well and the comparison below speaks for itself. Move the sliders to see the difference the resolution can make, and it is even more obvious when running the game on a 4K display.
If this was not clear, here is a zoomed in comparison that shows how much a difference a simple resolution upgrade and anisotropic filtering can make in a game (source).
When it launched back it 2010, Final Fantasy XIII was regarded as one the most gorgeous games on the Xbox 360, and it seems to hold up well next to the current generation releases even today, especially in 4K.
Final Fantasy XIII trilogy is available as a backward compatible release on the Xbox One and Xbox One X.