stage: Meta Crystal (1) +1

This is a remake of the N64 stage that was exclusive to the 1P Game, where you fought Metal Mario. It's been called different things... Metal Cave, Metal Mario's Stage, Metal Mario's Domain... I just chose the name from the OST. It's pretty small, so I recommend only 1-on-1 battles here. I originally had in mind to put some ladders underneath for decoration (the original stage had that red wire stuff from Super Mario 64), but I found that I could recover if I used them, so I placed functionality over decor.