Modder Joey4track is working on a mod that transforms all of Spelunky's art assets and music into a Metroid-themed adventure.
The mod is still a work in progress and unavailable to the public, but YouTuber BaerTaffy has released a video detailing an early build that he plays through the lion's share of in a half hour.
It's pretty impressive stuff with new background, item, and enemy skins. Arrow traps are transformed into Chozo statues, spiders turned into skrees, and jungle dwellers are now space pirates. There's even mammoth Kraid statues looming in the background. Oh, and the new ghost is a giant metroid, of course.
There's still a bit more work to go. Certain elements like ropes, boulders, and Olmec are disappointingly still sporting their default assets, but by and large it's a promising piece of work. Here's hoping Nintendo doesn't have a problem with the final build.