I'd love to see 104 in the game, the idea sounds a little complicated though, here's how I would see it.
104 is a basic flat stage, however it appears twice, one above and one below like a splitscreen. However, the top screen is actually a big platform, allowing you to jump between the worlds at will. This reps the main gimmick of the DS version of TWEWY, it also represents both realms in the game, RG and UG. The bottom platform is RG, it is normally very plain, but when the light goes green on the traffic light loads of Human NPC's flood the stage, essentially OHKOing anybody in the way. The way you combat this is to move to the UG at the top. This version is full of Noise, so you not only have to worry about players, but about them too.