There's a Earthbound 64 texture hidden in Super Smash Bros. Melee

In several trophies in Super Smash Bros. Melee, there's a reflection of a castle in the background. These reflections are barely noticeable in-game, but they are in fact there. You can see more information about these reflections at [You must be registered and logged in to see this link.]. As it's turns out, that's actually a screenshot from Earthbound 64 when it was in development. Here's the image in question:

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That image comes from this:

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I read the whole article on Melee that you linked.  There's lots of pretty interesting stuff left over in the game.