Map overlays

[iimarckus]

Stadium GS backgrounds are 320×240 JPGs like the previous games, but unlike the previous games it renders at 640×480 and upscales (map) backgrounds to match. It then overlays high‐resolution pictures of the destinations over the original background.

This is also how new destinations (Red’s cave, Rival’s cave, etc.) become visible on the map.

The effect is shown here:

Where are these overlays stored?