Fun thought, a different class in each world.

Seems pointless to me. I'd rather make more, closer friends in one world and feel like i'm still achieving stuff on my character. Rather than restarting constantly in a new world with a new character, meeting people for fleeting encounters which will ultimately end when you make a character on a different server. And constantly recreating characters isn't achieving anything. You aren't making money, aren't reaching a high level, you aren't developing your characters in any significant way.

This, pretty much. It sounds like a complete downgrade to MapleStory.