Rare was 49 percent owned by Nintendo in 2001 when Melee launched and Perfect Dark is even mentioned in the credits, it's not a legal issue. I assume this is a case of censorship since Perfect Dark was rated M and contained a decent amount of blood and swearing. Nintendo also published PD themselves in Japan
(and censored it) but Rare nominally published it elsewhere. Also, you can shoot down flying cars on the rooftop and through windows of the DataDyne building in the opening level of that game! Melee came out in the US just weeks after 9/11.
So the Proximity Mine (though called the Sensing Bomb in the Japanese version) became the Motion-Sensing bomb and given the appearance of a proximity mine from Goldeneye (and Smash 64.) It gets even weirder, in Europe the name reverts to Proximity Mine and the Carrington Institute from Perfect Dark is referenced but the Perfect Dark itself is not and the model remains the North American GoldenEye mode (which was also called the Proximity Minel!)
I set my language to Japanese hoping to see the proxy mines like the other Japanese differences (Virtual Boy in Trophy Gallery, metres instead of feet, etc.) but was disappointed. The GoldenEye (or rather, TOP SECRET) Proximity Mine remains the same, which furthers in my mind that it's censorship, especially if they bothered to include two versions of the Trophy Gallery living room, announcer voice, etc. on the disc.
EDIT: Interesting to note that the Cloaking Device that is only in Melee in the Smash Bros series is from Perfect Dark, same model and everything, though the description doesn't mention PD (TOP SECRET like the GoldenEye Proximity Mine) and Slippy from Star Fox (voiced by Chris Seavor of Rare) implies he invented it in Adventure Mode!
